Libyan militiamen have taken control of most government ministries in the capital Tripoli, the government said.
"We announce that most ministries, institutions and state bodies in the capital Tripoli are out of our control," a government statement said.
On Sunday, militiamen took control of the US embassy, with footage showing men cheering and jumping from the balcony into the swimming pool.
Prime Minister Abdullah al-Thinni has been reappointed after his resignation last week. He was appointed after elections earlier this year but resigned due to the current crisis.
The main militia group in control of Tripoli, Libya Dawn, has called on the previous parliament, the unelected General National Congress to resume its position, but the UN says it will only support the elected government under al-Thinni.