A Russian air strike on a military training base in western Ukraine killed at least nine people and injured 57 others, a local official said on Sunday.

The attack took the war closer to the border with Poland after a senior Russian diplomat warned that Moscow considers foreign shipments of military equipment to Ukraine “legitimate targets”.

The governor of the Lviv region, Maksym Kozytskyi, said Russian forces fired more than 30 cruise missiles at the Yavoriv military range, 19 miles (30km) north-west of the city of Lviv and 22 miles (35km) from Ukraine’s border with Poland.

The United States and Nato have regularly sent instructors to the range, also known as the International Peacekeeping and Security Centre, to train Ukrainian military personnel. The facility has also hosted international Nato drills.

Russian fighters also fired at the airport in Ivano-Frankivsk, a city in western Ukraine located 155 miles (250km) from the border with Slovakia and Hungary. Mayor Ruslan Martsinkiv said Russia’s goal is “to sow panic and fear”.

On Saturday, Russia bombarded cities across Ukraine, pounding Mariupol in the south, shelling the outskirts of the capital, Kyiv, and thwarting the efforts of people trying to flee the violence.

In Mariupol, which has endured some of the worst punishment since Russia invaded, efforts to take food, water and medicine into the port city and to evacuate civilians were prevented by unceasing attacks.

More than 1,500 people have died in Mariupol during the siege, according to the mayor’s office, and the shelling has even interrupted efforts to bury the dead in mass graves.

Talks aimed at reaching a ceasefire again failed on Saturday, and, while the US announced plans to provide another 200 million dollars to Ukraine for weapons, a senior Russian diplomat warned that Moscow could attack foreign shipments of military equipment.

Ukrainian President Volodymyr Zelensky accused Russia of trying to break his country apart, as well as starting “a new stage of terror” with the alleged detention of a mayor from a city west of Mariupol.

“Ukraine will stand this test. We need time and strength to break the war machine that has come to our land,” he said during his nightly address to the nation on Saturday.

Russian soldiers pillaged a humanitarian convoy that was trying to reach Mariupol and blocked another, a Ukrainian official said.

Ukraine’s military said Russian forces captured Mariupol’s eastern outskirts, tightening their siege of the strategic port. Taking Mariupol and other ports on the Azov Sea could allow Russia to establish a land corridor to Crimea, which it seized from Ukraine in 2014.

An Associated Press journalist in Mariupol witnessed tanks firing on a nine-storey apartment building and was with a group of hospital workers who came under sniper fire on Friday.

A worker shot in the hip survived, but conditions in the hospital were deteriorating. Electricity was reserved for operating tables, and people with nowhere else to go lined the corridors.

Among them was Anastasiya Erashova, who wept and trembled as she held a sleeping child. Shelling had just killed her other child as well as her brother’s child, she said, her scalp crusted with blood.

“No-one was able to save them,” she said.

In Irpin, a suburb about 12 miles (20km) north-west of central Kyiv, bodies lay out in the open in streets and in a park.

“When I woke up in the morning, everything was covered in smoke, everything was dark. We don’t know who is shooting and where,” resident Serhy Protsenko said as he walked through his neighbourhood. Explosions sounded in the distance. “We don’t have any radio or information.”

Mr Zelensky encouraged his people to keep up their resistance.

“We do not have the right to let up our defence, no matter how difficult it may be,” he said.

Later on Saturday, he reported that 1,300 Ukrainian soldiers had died since the Russian invasion began on February 24.

The first major city to fall, earlier this month, was Kherson, a vital Black Sea port of 290,000 residents.

Mr Zelensky said the Russians are using blackmail and bribery in an attempt to force local officials to form a “pseudo-republic” in the southern Kherson region, much like those in Donetsk and Luhansk, two eastern regions where pro-Russian separatists began fighting Ukrainian forces in 2014. One of the pretexts Russia used to invade was that it had to protect the separatist regions.

The president again deplored Nato’s refusal to declare a no-fly zone over Ukraine and said his country has sought ways to procure air defence assets, though he did not elaborate.

US President Joe Biden announced another 200 million dollars in aid to Ukraine, with an additional 13 billion dollars included in a Bill that has passed the House of Representatives and should pass the Senate within days.

Nato has said imposing a no-fly zone could lead to a wider war with Russia.

The Ukrainian president also accused Russia of detaining the mayor of Melitopol, a city 119 miles (192km) west of Mariupol. He called on Russian forces to heed calls from demonstrators in the occupied city for the mayor’s release.

In multiple areas around Kyiv, artillery barrages sent residents scurrying for shelter as air raid sirens wailed.

Britain’s Ministry of Defence said Russian forces that had been massed north of the capital had edged to within 15 miles (25km) of the city centre and spread out, probably to support an attempted encirclement.

A convoy of hundreds of people fleeing Peremoha, about 12 miles (20km) north-east of Kyiv, were forced to turn back under shelling by Russian forces that killed seven people, including a child, Ukraine’s defence ministry said on Saturday.

Moscow has said it would establish humanitarian corridors out of conflict zones, but Ukrainian officials have accused Russia of disrupting those paths and firing on civilians.

Ukraine’s deputy prime minister, Iryna Vereshchuk, said just nine of 14 agreed-upon corridors were open on Saturday, and that about 13,000 people had used them to evacuate around the country.

Ukraine’s military and volunteer forces have been preparing for an all-out assault on the capital.

Kyiv Mayor Vitali Klitschko said on Thursday that about two million people – half the metropolitan area’s inhabitants – had left and that “every street, every house … is being fortified”.

Mr Zelensky said on Saturday that Russia would need to carpet-bomb Kyiv and kill its residents to take the city.

“They will come here only if they kill us all,” he said. “If that is their goal, let them come.”

French and German leaders spoke with Russian President Vladimir Putin on Saturday in a failed attempt to reach a ceasefire.

According to the Kremlin, Mr Putin laid out terms for ending the war. For ending hostilities, Moscow has demanded that Ukraine drop its bid to join Nato and adopt a neutral status; acknowledge Russia’s sovereignty over Crimea, which it annexed from Ukraine in 2014; recognise the independence of separatist regions in the country’s east; and agree to demilitarise.

In Mariupol, where electricity, gas and water supplies have been knocked out, aid workers and Ukrainian authorities described an unfolding humanitarian catastrophe.

Aid group Doctors Without Borders said residents are dying from a lack of medication and are draining heating pipes for drinking water.

Russian forces have hit at least two dozen hospitals and medical facilities, according to the World Health Organisation.

The Russian invaders appear to have struggled far more than expected against determined Ukrainian fighters. Nevertheless, Russia’s stronger military threatens to grind down Ukrainian forces.

Russian deputy foreign minister Sergei Ryabkov warned on Saturday that his country could attack foreign shipments of military equipment to Ukraine. He said sending equipment is “an action that makes those convoys legitimate targets”.

Thousands of soldiers on both sides are believed to have been killed along with many civilians, including at least 79 Ukrainian children, its government says. At least 2.5 million people have fled the country, according to the United Nations refugee agency.