Al Shabaab militia
A Somali soldier runs to hold position as Al Shabaab militia storms a government building in Mogadishu, Somalia March 23, 2019. Image Credit: Reuters

Mogadishu, Somalia: Somalia's Al Shabaab stormed a government building on Saturday, detonating a suicide car bomb in the heart of the capital, Mogadishu, with at least 15 people, including an assistant minister, killed during an ensuing gun battle.

"I saw the dead bodies of four people, one of them in police uniform," said witness Abdulahi Mohammad to AFP, while Senator Ilyas Ali Hassan named the deceased minister as Saqar Ebrahim Abdalla, who was killed separately.

The large explosion shook the centre of Mogadishu and a large plume of smoke rose above the scene of the blast, a building that houses Somalia's ministries of labour and works.

It was the latest bombing claimed by Al Shabaab, an Islamist group that is fighting to establish its own rule in Somalia.

Police later said the fighting at the building had ended and that the premises had been completely secured.

"The building was secured by security forces. The four militants who attacked the building were shot dead. Another militant was a suicide car bomber and so he also died," Major Ali Abdullahi, a police officer told Reuters.

Abdullahi said ten people, including assistant labour minister Saqar Ebrahim Abdala and police personnel, had died.

Police said earlier that some 20 people had been injured in the assault, which began when a suicide bomber detonated a car bomb, allowing other militants to storm the building.

Dr Abdikadir Abdirahman, director of Amin Ambulance Service told Reuters soon after the assault begun that people were trapped inside the building and that it was not possible to rescue them because of a heavy exchange of fire.

Al Shabaab told Reuters one of its fighters had rammed the ministry building with a car bomb allowing others to enter.

"We are inside the building and (the) fighting goes on. We shall give details later," Abdiasis Abu Musab, Al Shabaab's military operation spokesman said during the attack.

Al Shabaab, which is trying to topple Somalia's western backed central government, was ejected from Mogadishu in 2011 and has since been driven from most of its other strongholds.

But it remains a threat, with its fighters frequently carrying out bombings in Somalia and neighbouring Kenya, whose troops form part of the African Union mandated peacekeeping force AMISOM that helps defend Somalia's central government.