TRIPOLI, July 3 (Xinhua) -- The United Nations Support Mission in Libya (UNSMIL) on Wednesday condemned the deadly attack on a migration center in the capital Tripoli, which left dozens killed.

The UNSMIL said it strongly condemns the attack on a compound in Tajoura where migrants were detained, which led to at least 44 deaths and more than 130 severe injuries, adding that this is the second time this facility, hosting about 600 migrants, has been attacked.

"This attack clearly could constitute a war crime, as it killed by surprise innocent people whose dire conditions forced them to be in that shelter," said UN Special Envoy to Libya Ghassan Salame.

"The absurdity of this ongoing war has led this odious bloody carnage to its most hideous and most tragic consequences," Salame added.

The UNSMIL called for an immediate stop to "violations and attacks on civilians in Libya," reminding all the parties in Libya of their obligations under international laws in force.

Both of the east-based army and the rival UN-backed government have exchanged accusations for the deadly attack.

The east-based army has been leading a military campaign since early April to take over Tripoli from the internationally-recognized Government of National Accord, which has so far killed hundreds of people, injured thousands of others, and caused tens of thousands to flee their homes.

Libya has been suffering escalating violence and political turmoil since the fall of late leader Muammar Gaddafi's regime in 2011.