A truck bomb exploded at a checkpoint in the central Somali town of Beledweyne on Saturday, killing at least 10 people and obliterating nearby buildings, a police officer said.
It was not immediately clear who was responsible but the Islamist group al Shabaab frequently carries out bombings in the Horn of Africa country.
"So far I have seen 10 dead people including soldiers and civilians and over a dozen others injured, but the death toll is sure to rise," police officer Ahmed Aden told Reuters.
Beledweyne is in central Somalia's Hiran region which has recently witnessed battles between the military and al Shabaab.
Aden said the dead included five police officers who fired on the truck in a failed attempt to stop it ramming the checkpoint. Nearby buildings and shops were reduced to rubble, along with the checkpoint, he added.