At least 3 people were killed in central Somalia after unidentified gunmen opened fire on a bus carrying passengers, in what officials are calling a horrific attack on innocent civilians.

Assailants armed with AK-47 riffles wearing face masks fired on the passengers from a four-wheel drive vehicles on a desolate road near Godad location in eastern Mudug region.

Men, women and children are among the dead and injured, local officials said.

It is not yet clear the motive behind the shooting of the bus, and no group has so far claimed responsibility for the deadly attack.

This comes a day after two nomad girls were gang rapped in the area, which been been beset by inter-clan conflict in the past few months.