Somalia's security forces are battling gunmen in a building in Mogadishu, hours after a suicide car bomb attack on a busy street left at least 20 people dead, security sources say.
Somali militants holed up as battle rages in Mogadishu
The Islamist group al-Shabab, which is linked to al-Qaeda, was forced out of Mogadishu in 2011 but continues to mount regular attacks in the city. The US has sharply increased its air strikes against the group since President Trump took power.