Up to 15 Al-Shabaab fighters were killed when a vehicle laden with explosives went off in a house in Buloburte town, some 200 km north of the capital Mogadishu.
It was not clear if the militants died while packing the car with bombs for a suicide mission or if it went off afterwards while they were in the vicinity.
Resident said that they believed 20 more were wounded, local media houses in Mogadishu reported.
"The militants were most likely packing the vehicle with explosive devices or in the house when the deadly incident occurred," said a resident who asked the media not to release their name.
Residents said the militants were on Tuesday busy burying the dead while keeping the scene of the blast sealed off from the general public.
It is not the first time vehicles being assembled for suicide missions in Somalia have exploded while still under the care of the militants.
On some occasions, residents in the affected areas, especially in Mogadishu, said that foreign jihadists (holy warriors) were among those killed or injured.
Sometimes landmines have also blown up while being planted by the militants.
In another development, the government of Seychelles Monday handed nine convicted pirates to Puntland State, a semi-autonomous authority in north-eastern Somalia.
Mr Said Mohamed Raghe, the Puntland Minister for Ports and Anti-Piracy, said that his authority had long advocated for the transfer of the pirates to finish their sentences in their home country.
"We would like hundreds of sentenced Somali pirates repatriated so that they serve their jail terms in prisons in Somalia,” said Minister Raghe.
Puntland officials indicated that the nine were part of the 25 pirates held in the Seychelles and looked forward to receiving the others.
