TRIPOLI, July 15 (Xinhua) -- The United Nations High Commission for Refugees (UNHCR) on Monday called for closure of detention centers of illegal immigrants in Libya.

"We continue to call for the closure of all detention centers in Libya. 200 people were brought to Tajoura detention center," the UNHCR tweeted.

Earlier in July, dozens of illegal immigrants were killed or injured in an attack on a reception center for illegal immigrants in the east of the capital Tripoli.

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

The army has been leading a military campaign since early April to take over Tripoli from the government.

According to the World Health Organization, the fighting has so far killed more than 1,000 people and injured over 5,700 others, while more than 100,000 fled their homes because of the armed conflict.

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