The Libyan Special Deterrent Force arrested 61 militants involved in the recent attack on Tripoli’s M’etiga International Airport, said the force in a statement on Sunday.

“During the treacherous attack on M’etiga airport and the attempt to target the prison, 61 people were arrested, most of whom were caught carrying arms and taking part in the attack on the airport,” said the statement.

The statement said that investigation continues with the arrested gunmen, and that six of them were released.

Heavy clashes broke out on Monday at the airport after an armed group attacked the security force of the airport, killing 21 people and injuring 69 others, including civilians.

The UN-backed government issued a statement condemning the attack, saying that the attack “aimed at freeing IS, al-Qaida and other terrorists from the detention center supervised by the Interior Ministry’s Special Deterrence Force inside the airport.”

The airport was reopened on Saturday after five days of closure.