The Islamist Al Shabaab movement in Somalia on Monday said it was the target of recent series explosions that rocked the insurgent-held part of the Somali capital Mogadishu and accused an unnamed group for the attacks.

Several explosions, the latest on late Sunday night, recently took place in the main Bakara market in Mogadishu and other Al Shabaab strongholds, have remained a mystery to the group and local Mogadishu residents but the movement now says another group which it did not name was behind the attacks.

"The Mujahideens were able to apprehend those suspected of being behind the recent explosions in Mogadishu and they claimed to be fighters for a group which claims to be Mujahideen and that group requested the release of the suspected men," Ali Mohamoud Rageh, spokesman for Al Shabaab told reporters in Mogadishu.

Three men were killed in Sunday night's explosion in Mogadishu and Al Shabaab said the men belonged to a local group and were planting the bombs in the group's strong-hold.

Insurgent-held side of the Somali capital Mogadishu grew tense as the news of the explosion and the death of the three alleged Islamist fighters emerged with intense gunshots heard throughout insurgent's strongholds.

The Islamist rebel group of Al Shabaab has had an uneasy relationship with the other smaller insurgent group of Hezbul Islam which it fought over the control of the strategic southern Somali port city of Kismayu last year.

Hezbul Islam, whose fighters were driven from Kismayu last year, has not so far commented on the latest developments, but on Sunday confirmed that its forces fought with Al Shabaab fighters over the control of a district on the border with Kenya, a move the group has previously avoided.

Al Shabaab spokesman on his part accused the unnamed group of claiming of fighting with Al Shabaab forces in Qoryoley district, saying his group fought with what he called "apostate forces trained by Kenya and sent to capture the district".

This is the first such public spat between the two groups which have been allied in their fight against Somali government forces and the African Union peacekeeping forces in south-central Somalia, part of the East African country in chaos for nearly two decades.