Qatar ordered the embassy of Chad be closed and gave its diplomats 72 hours to leave, the Qatari foreign ministry said on Thursday, accusing the African country of joining a “campaign of blackmail” with its decision to shutter the Qatari embassy.

Qatar is involved in a row with four Arab countries, including Saudi Arabia and the United Arab Emirates, over allegations that Doha supports terrorism. Qatar denies the charges.

Chad said on Wednesday it was giving Qatari diplomats 10 days to leave the country, accusing Qatar of trying to destabilise the central African nation through its northern neighbour Libya.

The director of the Qatari foreign ministry’s media department said the timing of the Chadian decision shows that it “comes within the campaign of political blackmail against the State of Qatar with the intention of joining the siege countries for very well known reasons”.

Qatar refers to Saudi Arabia, the UAE, Bahrain and Egypt as the “siege countries” for imposing sanctions on it.

Senegal said this week it had returned its ambassador to Qatar after having recalled him three months ago, in a bid to encourage a peaceful resolution to the feud.

Chad did not provide any details to support the accusation that Doha was trying to destabilise it through Libya.

The UAE and Qatar, which both played key roles in backing rebels who toppled Muammar Gaddafi in 2011, have emerged as rivals on the battlefield with conflicting interests in Libya.

The vacuum created by Gaddafi’s downfall led to a flood of weapons from state arsenals into the hands of Islamist groups who then pushed south into Africa’s Sahel nations where they launch attacks on military and civilian targets.