The International Organization for Migration (IOM) on Saturday condemned the killing of illegal immigrants at a detention center in the Libyan capital Tripoli.

"IOM condemns Friday's senseless killing and the use of live rounds against migrants protesting the appalling conditions in detention," IOM said in a statement.

Six people were killed, and at least 24 others were injured at the Mabani detention center in Tripoli when armed guards opened fire following a riot and an attempted escape, IOM said.

However, the Libyan interior minister denied the six deaths, confirming that only one person was killed "accidentally while leaving the center."

The United Nations High Commissioner for Refugees (UNHCR) had said earlier Friday that it was "increasingly alarmed about the humanitarian situation for asylum seekers and refugees in Libya."

"Following a large-scale security operation by the Libyan authorities in the past week, arrests and raids have been taking place in many parts of Tripoli, targeting areas where asylum seekers and migrants are living," it said.

The UNHCR on Saturday provided medical assistance for a group of asylum seekers after they escaped from a detention center in the Libyan capital Tripoli.

Libya has been suffering insecurity and chaos since the fall of the late leader Muammar Gaddafi in 2011, making the North African country a preferred point of departure for illegal immigrants who want to cross the Mediterranean Sea to European shores.

Those rescued and arrested live in overcrowded reception centers across Libya, despite repeated international calls to close the centers.

(With input from agencies)