MOGADISHU, Somalia (AP) — Somali authorities on Sunday appeared to have ended a deadly attack on a hotel in the capital in which at least 20 people were killed.

It took Somali forces more than 30 hours to contain the gunmen who had stormed Mogadishu's Hayat Hotel on Friday evening in an assault that started with loud explosions.

Ismail Abdi, the hotel's manager, told the AP that while the siege has ended, security forces were still working to clear the area.

No more gunfire could be heard after 9 a.m. local time. Onlookers gathered outside the gates of the badly damaged hotel on Sunday morning, surveying the scene.

Police are yet to give a detailed explanation of how the attack unfolded. It remains unclear how many gunmen entered the hotel.

The Islamic extremist group al-Shabab, which has ties with al-Qaida, claimed responsibility for the attack, the latest of its frequent attempts to strike places visited by government officials.

The attack on the hotel is the first major terror incident in Mogadishu since Somalia’s new leader, Hassan Sheikh Mohamud, took over in May.

U.N. Secretary-General Antonio Guterres condemned the attack, according to a spokesman's statement that said the U.N. supports the people of Somalia ”in their fight against terrorism and their march towards peace.”