The assault on the Hayat Hotel has triggered a fierce gunfight between security forces and terrorists who are still holed up inside the building.
Al Shabab terrorists have attacked a hotel in the Somali capital Mogadishu in a hail of gunfire and explosions, with casualties reported, security sources and witnesses have said.
The assault on the Hayat Hotel on Friday triggered a fierce gunfight between security forces and the terrorists who are still holed up inside the building, security official Abdukadir Hassan told AFP news agency.
"A huge blast went off a few minutes before the gunmen forced their way into the hotel," Hassan said.
"We don't have the details so far but there are casualties, and the security forces are now engaging with the enemy who are holed up inside the building," he added.
Witnesses said a second blast occurred outside the hotel a few minutes after the first, inflicting casualties on rescuers and members of the security forces and civilians who rushed to the scene after the first explosion.
"The area is cordoned off now and there is exchange of gunfire between the security forces and the gunmen," said one witness, Mohamed Salad.
The Al Qaeda-linked group, which has led an insurrection against Somalia's central government for about 15 years, claimed responsibility.
Earlier this week, the United States announced that its forces had killed 13 Al Shabab terrorists in an air strike in the central-southern part of the country as the gunmen were attacking Somali forces.
The US has carried out several air raids on the group in strikes in recent weeks.
In recent weeks, Al Shabab terrorists have also waged attacks on the Somalia-Ethiopia border, raising concerns about a possible new strategy.
Al Shabab terrorists were driven out of the capital in 2011 by an African Union force, but the group still controls swathes of countryside and frequently strikes civilian and military targets.