At least 48 Kenyans have been hacked or burnt to death in ethnic clashes between two rival groups, Pokomo and Orma, in southeastern Kenya. Police say the tragedy is the worst single attack since deadly post-election violence four years ago.

Said Mgeni, a local resident, says the attack began at dawn when a group of 200 Pokomo gang members raided an Orma community torching all the houses.

Police say 34 people were hacked and 14 others were burnt to death with a whole Orma village on an island in the Tana River put to ashes.

“They [victims] include 31 women, 11 children and six men,” regional deputy police chief Joseph Kitur said.

The deadly fighting did not spare the cattle either, with 60 cows also slashed to death by the attackers.

Lawmaker Danson Mungatana, who represents the area, says the killings are “revenge attacks” in a string of tit-for-tat clashes and cattle raids. Last week the Orma attacked the Pokomo and burned down more than 100 houses.

“Now the Pokomo revenged [sic] by killing about 50 people,” Mungatana said.

The Kenyan tribes of Pokomo and Orma have been at odds since 2001, when at least 130 people were killed in a string of clashes in the same district and by the same two communities. The rivalry is centered around access to land and a river.