An attack by gunmen on a public bus in Ethiopia's western Gambella region has left 19 people dead and wounded eight others, an official said.
"The attack took place yesterday (Monday), around 2pm... I suspect it was an anti-peace element we consider as rebels," Omot Odeng Olol, the regional president, told the AFP news agency on Tuesday.
Omot said the suspected rebels armed with machine guns stole money and clothes from the passengers before opening fire on them.
He said the gunmen have not yet been caught.
"We deployed a number of forces and we are still looking, and they are not yet caught," he said, adding that he does not expect the assaillants to launch further attacks in the area as security has been beefed up.
Omot said when police arrived at the scene bodies were strewn on the ground as the injured were taken to a nearby hospital.
"That kind of thing is the very worst you can imagine," he said.
No group has claimed responsibility for the attack.
Ethiopia's Gambella region, which lies some 700km (430 miles) to the west of the capital Addis Ababa, is one of the most fertile and resource-rich areas of the country.
In January the US-based Human Rights Watch accused Addis Ababa of forcing thousands of villagers from their land to make way for commercial farming developments, leaving people impoverished and hungry.
At least 3.6 million hectares (8.8 million acres) have been leased to foreign and state-owned firms since 2008, with state security using force to drive people from off their land, HRW said.