Heavily armed men stormed a prison in southwest Nigeria and freed hundreds of prisoners.

575 inmates were still on the run after the attack on Friday evening, said the prison administration spokesman in Oyo state on Saturday.

According to the Nigerian newspaper The Premium Times, a total of 837 detainees escaped and 262 were taken back into custody.

The heavily armed attackers blew up the wall with dynamite after a fight with the guards, the spokesman said.

He did not provide any information about the dead or injured.

The most populous country in Africa is plagued by crime and violence.

Large parts of the country are controlled by criminal groups.

Around 240 prisoners were released in September in an attack on another prison in the central Nigerian state of Kogi.

In April, more than 1,800 prisoners escaped in an attack on another detention center in the south-east of the country.