Hundreds of Armenians blocked streets in the capital Yerevan late on Thursday and called for the resignation of Prime Minister Nikol Pashinyan over a ceasefire deal that locked in Azeri territorial gains in Nagorno-Karabakh last month.

Pashinyan has rejected the calls to resign over what his opponents say was his disastrous handling of a six-week conflict between Azerbaijan and ethnic Armenian forces over the Nagorno-Karabkh enclave and surrounding areas.

Protesters chanted “Nikol is a traitor” and police officers detained several people, witnesses told Reuters.

Earlier on Thursday, a coalition of 17 opposition parties named former premier Vazgen Manukyan as a potential caretaker prime minister to replace Pashinyan until snap parliamentary elections are held.

The move has no legal force, but illustrates public anger against Pashinyan who has accepted full responsibility for the outcome of the conflict, but said he is now responsible for ensuring national security and stabilising Armenia.

Former National Security Service Chairman Artur Vanetsyan said Manukyan could serve as a prime minister without a party affiliation and then call snap elections that he himself would not take part in.

The ceasefire signed by leaders of Armenia, Azerbaijan and Russia on Nov. 10 halted military action in and around Nagorno-Karabakh, an enclave internationally recognised as part of Azerbaijan but populated by ethnic Armenians.

Some 2,000 Russian peacekeeping troops are now being deployed to the region.

Large areas in Nagorno-Karabakh previously controlled by ethnic Armenians were handed over to Azerbaijan, whose forces had captured territory including areas that Baku lost in an earlier war in the 1990s.