TRIPOLI (Reuters) - At least five civilians were killed and 12 others wounded among dozens of casualties in recent fighting in the Libyan migrant smuggling hub of Sabratha, the United Nations said on Monday.

Sabratha’s university hospital has twice been hit by shelling, rendering the emergency and surgery units unusable, the U.N. Libya mission said in a statement.

The clashes have pitted the Anas al-Dabbashi brigade, a powerful armed group previously known for migrant smuggling, against the Operations Room to combat the Islamic State, a group formed last year to oust jihadists from Sabratha.

The fighting broke out when a Dabbashi brigade member was shot dead at a checkpoint, but the brigade’s head has said the underlying cause was the group’s move to stop the departure of migrant boats to Italy following a deal with the U.N.-backed government in Tripoli.

Sabratha had been the most common departure point for migrants setting off toward Italy from Libya, until a sudden drop in crossings from July.

The health ministry in Tripoli said on Friday that, overall, at least 26 people including combatants had been killed and 170 wounded in nearly two weeks of fighting.