HOMS, Syria — Ahmed al-Sharaa, the leader of the Syrian rebel group that overthrew Bashar al-Assad’s government, was named head of a new interim government, according to the Syrian news agency, citing a government spokesperson.

The spokesperson, Col. Hassan Abdul Ghani, speaking on behalf of a coalition of military factions, said Sharaa would take over duties of the country’s president on an interim basis. He also announced that the country’s old constitution and parliament had been dissolved, as had several political parties affiliated with the former regime.

Sharaa was already the de facto head of Syria’s government ever since a coalition of rebel fighters anchored by his group, the Hayat Tahrir al-Sham or HTS, swept through most of Syria and ousted the former regime that had survived a decade of fighting in a grinding civil war.

The spokesperson also said that Sharaa had been authorized to form a temporary legislative council, until a new constitution is approved and comes into effect.

Celebratory gunfire and street celebrations broke out in the capital Damascus and the city of Homs as news of Sharaa’s appointment was announced late Wednesday.