Several countries have violated an arms embargo on Libya which they had agreed to uphold a week ago at a summit in Berlin, the United Nations (UN) said on Saturday.

"Over the last ten days, numerous cargo and other flights have been observed landing at Libyan airports in the western and eastern parts of the country providing the parties with advanced weapons, armored vehicles, advisers and fighters," the UN mission to Libya said in a statement.

It warned that the ongoing violations risked plunging the country into a renewed and intensified round of fighting. It did not name the countries having violated the arms embargo.

Last Sunday, foreign powers backing opposing camps in Libya agreed at a summit hosted by Germany and the UN to push the parties to a lasting ceasefire and respect an existing UN arms embargo.

The Berlin summit had gathered top officials from the United Arab Emirates, Egypt, Turkey as well as western countries such as the U.S., France, Britain, and the European Union.

Libya has been engulfed in chaos after the toppling of its former leader Muammar Gaddafi in 2011. Another wave of conflict broke out between Khalifa Haftar's Libyan National Army and the UN-recognized Government of National Accord since April 2019.

The two sides agreed to a ceasefire on January 12, which provided a much-needed respite for civilians in the capital. But the UN warned that the fragile peace is now threatened by the ongoing transfer of fighters, weapons, ammunition and advanced systems to the parties by member states.