Officials from Russia and Ukraine are set to engage in another round of diplomatic talks as Moscow’s forces continue to pound away at the Ukrainian capital Kyiv and other cities across the country.

Shortly before dawn on Tuesday, large explosions thundered across the capital while Russia pressed its advance on multiple fronts.

A series of Russian strikes hit a residential neighbourhood in Kyiv, igniting a huge fire and a frantic rescue effort in a 15-storey apartment building. At least one person was killed and others remain trapped inside.

Elsewhere, a convoy of 160 civilian cars left the encircled port city of Mariupol along a designated humanitarian route, the city council reported, in a rare glimmer of hope a week and a half into the lethal siege that has pulverised homes and other buildings and left people desperate for food, water, heat and medicine.

The latest negotiations, held via video conference, were the fourth round involving higher-level officials from the two countries and the first in a week. The talks ended on Monday without a breakthrough after several hours, with an aide to Ukrainian President Volodymyr Zelensky saying the negotiators took “a technical pause” and planned to meet again on Tuesday.

The two sides had expressed some optimism in the past few days. Mykhailo Podolyak, the aide to Mr Zelensky, tweeted that the negotiators would discuss “peace, ceasefire, immediate withdrawal of troops & security guarantees”.

Previous discussions, held in person in Belarus, produced no lasting humanitarian routes or agreements to end the fighting.

In Washington, White House press secretary Jen Psaki said that while the Biden administration supports Ukraine’s participation in the talks with Russia, Russian President Vladimir Putin would have to show signs of de-escalating in order to demonstrate good faith.

Overall, nearly all of the Russian military offensives remained stalled after making little progress over the weekend, according to a senior US defence official who spoke on condition of anonymity to discuss the Pentagon’s assessment. Russian troops were still about nine miles (15 kilometres) from the centre of Kyiv, the official said.

The official said that Russian forces have launched more than 900 missiles but that Ukraine’s airspace is still contested, with Russia not achieving total air superiority.

Ukrainian authorities said two people were killed when the Russians struck an airplane factory in Kyiv, sparking a large fire. The Antonov factory is Ukraine’s largest aircraft plant and produces many of the world’s biggest cargo planes.

Russian artillery fire also hit a nine-storey apartment building in the northern Obolonskyi district of the city, killing two more people, authorities said.

And a Russian airstrike near a Ukrainian checkpoint caused extensive damage to a downtown Kyiv neighbourhood, killing one person, Ukraine’s emergency agency said.

In an area outside Kyiv, Fox News reporter Benjamin Hall was injured while reporting and taken to hospital, the network said.

In Russia, the live main evening news program on state television was briefly interrupted by a woman who walked into the studio holding a poster against the war. The OVD-Info website that monitors political arrests said she was a Channel 1 employee who was taken into police custody.

A town councillor for Brovary, east of Kyiv, was killed in fighting there, officials said. Shells also fell on the Kyiv suburbs of Irpin, Bucha and Hostomel, which have seen some of the worst fighting in Russia’s stalled attempt to take the capital, local authorities said.

Airstrikes were reported across the country, including the southern city of Mykolaiv, and the northern city of Chernihiv, where heat was knocked out to most of the town. Explosions also reverberated overnight around the Russian-occupied Black Sea port of Kherson.

Nine people were killed in a rocket attack on a TV tower in the western village of Antopol, according to the region’s governor.

In the eastern city of Kharkiv, firefighters doused the smouldering remains of a four-storey residential building. It was unclear whether there were casualties.

In Mariupol, where the war has produced some of the greatest suffering, the city council did not say how many people were in the convoy of cars headed westward for the city of Zaporizhzhia. But it said a ceasefire along the route appeared to be holding.

Previous attempts to evacuate civilians and deliver humanitarian aid to the southern city of 430,000 were thwarted by fighting.

Ukraine’s military said it repelled an attempt on Monday to take control of Mariupol by Russian forces, who were forced to retreat. Satellite images from Maxar Technologies showed fires burning across the city, with many high-rise apartment buildings heavily damaged or destroyed.

The Kremlin-backed leader of the Russian region of Chechnya said on a messaging app that Chechen fighters were spearheading the offensive on Mariupol.

Robert Mardini, director-general of the International Committee of the Red Cross, said the war has become “nothing short of a nightmare” for those living in besieged cities, and he pleaded for safe corridors for civilians to leave and humanitarian aid to be brought in.

The Russian military said 20 civilians in the separatist-controlled city of Donetsk in eastern Ukraine were killed by a ballistic missile launched by Ukrainian forces. The claim could not be independently verified.

The UN has recorded at least 596 civilian deaths since Russia invaded Ukraine on February 24, though it believes the true toll is much higher. Millions more have fled their homes, with more than 2.8 million crossing into Poland and other neighbouring countries in what the UN has called Europe’s biggest refugee crisis since the Second World War.