A suspected car bomb has exploded in Bakin, a main entrance to Baidoa, where the government is based.
A small minibus that carries passengers from the capital Mogadishu to Baidoa, a seat for the Somali government, was reported to have exploded at a government checkpoint quite near Baidoa.
Witnesses said they had seen dead bodies and seriously injured people lying around.
Casualties cannot be verified yet.
It is not clear what caused the explosion or if the bus was packed with explosives.
On 18 September, double suicide car bombings had taken place in Baidoa as the Somalia president Abdulahi Yusuf escaped the suicide attacks but his younger brother died in the explosions.