At least 600 inmates have escaped in a jailbreak in Nigeria’s capital city, officials said.

The attack was blamed on Islamic extremist rebels.

About 300 prisoners have been recaptured, authorities said.

The “very determined” rebels attacked the Kuje maximum prison in Abuja on Tuesday night with “very high-grade explosives”, killing one guard on duty, according to Shuaib Belgore, permanent secretary of Nigeria’s Ministry of Interior.

Explosions and gunfire were heard at about 10pm in the Kuje area of Abuja when the attackers arrived and forced their way into the prison through a hole blown in a wall.

The rebels who attacked the prison have waged an insurgency in the country’s north-east for over a decade.

Their attack on the detention facility freed many of their members who are inmates, prison officials said.

“We understand they are Boko Haram. They came specifically for their co-conspirators,” said Mr Belgore.

“Right now, we have retrieved about 300 out of about 600 that got out of the jail.”

Nigeria’s jihadi rebels have carried out several jailbreaks in the country’s north-east in recent years, but this is the first in the capital city.

Nigeria’s extremist insurgency, carried out by Boko Haram and an offshoot known as the so-called Islamic State Central African Province, is blamed for violence that has caused the deaths of more than 35,000 people and displaced more than two million people, according to the UN.

The prolonged instability, hunger and lack of health services caused by the insurgency have indirectly caused the deaths of more than 300,000 additional people, says the UN.

The extremists’ violence is the most serious security challenge in Nigeria, Africa’s most populous country with 206 million people, which also is battling violence in the north-west by rebellious herdsmen and a separatist movement in the country’s south.