Eight people were killed in a car bombing near a school in Somalia's capital Mogadishu on Thursday, police said, the latest attack claimed by Al-Shabaab in the country.

Anguished parents rushed to the scene of the attack, which severely damaged the school building, with injured students taken to hospitals around the city.

Somalia police spokesman Abdifatah Adan said in a brief statement that eight civilians were killed and 17 others wounded, without giving further details.

Security official Mohamed Abdillahi told AFP the explosion was caused by a car bomb, but added: "We don't know the target of the attack."

Witnesses said a large convoy carrying troops from AMISOM, the African Union force fighting the Al-Qaeda linked Al-Shabaab group, was passing through the area when the bomb went off.

"I was close to the area when the blast occurred, there was an AMISOM convoy... passing by," Said Ibrahim told AFP.

Al-Shabaab claimed responsibility for the bombing, saying it was aimed at "military trainers."

The militants frequently carry out attacks in the capital and elsewhere in the country against civilian, military and government targets.

"Everyone was shocked and the scene was really horrible," said Naima Ali, whose daughter was among the lucky ones to escape the carnage unharmed.

"I saw some of the students bleeding," Ali told AFP.

Mohamud Omar, whose cousin was at the school when the attack occurred, said the blast left a trail of devastation in its wake, with backpacks scattered under the debris.

"The blast destroyed the whole area and left the road in ruins, thanks to God that most of the students were unharmed despite the huge damage the explosion caused," he told AFP.

Ahmed Bare, a security guard at a nearby building, told AFP: "The school building was badly damaged and some of their school buses destroyed."

The director of Mogadishu's Aamin ambulance service, Abdikadir Abdirahman, shared photos of the rubble-strewn scene on Twitter, calling the bombing "a tragedy".