The death toll from the twin explosions against a popular restaurant in Somalia's capital Mogadishu has risen to 18, police said Saturday.

"So far the death toll from the explosion has reached 18 and many more were injured in the explosions that were perpetuated by anti-peace elements. Police are working to arrest those behind this," Mohamed Daahir, local district police commander told reporters.

Witnesses said a car laden with explosives was parked outside the Village Restaurant in Mogadishu, and minutes after it exploded, a suicide bomber detonated himself inside the eatery, which was popular with city residents.

Dozens of cars parked outside the restaurant were also destroyed in the explosions. Witnesses said dead bodies and charred wreckage of cars burnt in the explosion were all around the area.

"The site turned like a war zone. Dead bodies lay all around the area. Cars burning and the outside walls of the restaurant destroyed," eyewitness Mohamed Yusuf told Xinhua.

It was the second time that the restaurant in Mogadishu's Hamarweyne business district had been targeted by deadly explosions claimed by Islamist militant group Al Shabaab.

The restaurant is one of the top eateries opened in the capital after security improved following the ouster of the radical Islamists from Mogadishu.

No group has so far claimed responsibility for the attack but the Al Shabaab rebels had said they would target government workers and the African Union peacekeeping mission in Somalia (AMISOM).

Mogadishu has seen an increase in explosions for the past months targeting government installations, AMISOM forces as well as restaurants and hotels.

Somali security forces have tightened security in the capital since the upsurge of attacks blamed on the Islamist fighters of Al Shabaab.

Al Shabaab, which is linked to Al Qaeda, controls few areas in the south and center of Somalia, but has managed to launch deadly attacks in the capital and some other areas.