The U.S. government has asked it citizens to leave Burundi as soon as possible after 87 people were killed Friday, in an escalation of the violence surrounding the disputed third term of President Pierre Nkurunziza.

The State Department said Sunday that due to continuing violence it has ordered the departure of non-emergency U.S. government personnel and dependents of U.S. government employees from Burundi.

In a travel warning the State Department said the U.S. Embassy can only offer limited emergency services to U.S. citizens in Burundi.

Friday's violence was caused by attacks on three army installations. More than 300 people have been killed and about 215,000 others have fled the country since April, when it was announced that Nkurunziza would stand for a third term. Nkurunziza won elections in July.