At least one American is among the 27 who died in a terrorist attack on a hotel in Somalia on Saturday, and the U.S. State Department said it is still working to confirm whether other American citizens were hurt or killed in the assault.

Al Shabaab, an Islamic terrorist group linked to al Qaeda, claimed responsibility for the attack that lasted more than 14 hours. The assault on the Asasey hotel in the Somali port of Kismayo began with a suicide bomber ramming a car packed with explosives and continued with a long gun battle, leaving 27 people dead and 56 injured, Somalia's Minister for Planning and Development Aden Ibrahim Aw Hirshi said Saturday.

Fourteen people were airlifted to Mogadishu, the Somali capital, for treatment, Aw Hirshi said.

"We send our sincere condolences to the friends and families of the victims killed in the attacks in Kismayo and wish the injured a speedy recovery," a State Department spokesperson said.

The United Nations and multiple countries condemned the attacks. The Special Representative of the Chairperson of the African Union Commission for Somalia, Ambassador Francisco Madeira, said Somalia had made great strides in taking back territory from the terrorist group. This act of violence, he added, was meant to undermine that progress.

"This is an attack meant to derail progress in Somalia as the country rebuilds and consolidates the gains made on peace and security," Madeira said. "The attackers are a group of people with criminal, murderous and destructive agenda. They cannot claim to be fighting to bring good governance to the country."

A view of Asasey Hotel after an attack, in Kismayo , Somalia, on July 13, 2019. AP

The State Department said that the U.S. would continue to work with local authorities to support "a credible, democratic electoral process in Jubaland," a region in southern Somalia that will hold an election later this summer.

The U.S. reopened a diplomatic mission in Mogadishu last December for the first time in over 15 years. The U.S. embassy in Somalia was closed in 1991 when all diplomatic personnel were evacuated as the country fought a civil war.

"We condemn these attacks and will continue to work with our Somali and international partners in the fight against violent extremism in Somalia," the State Department spokesperson said.