Although police and army spokesman could not give an exact toll, one politician said at least 23 people had been killed and blamed Muslim herdsmen for the attacks.
The army said the first attack on Kankuru village near the flashpoint state capital of Jos happened around 7:00 am.
“Presently the casualty figures are not yet known. But there are casualties,” Captain Salisu Mustapha, a spokesman for the military special task force deployed in the region, told AFP.
A second village, Kushen, had also been attacked, he added.
Around 200 attackers, armed with guns and machetes, had stormed the mainly Christian villages. They were suspected to be Muslim herdsmen from the Fulani tribe.
The military had moved into the area to try to contain the violence, he added.
Plateau state police spokesman Emmanuel Abuh said his men were also patrolling there and that the fighting was still going on.
“It’s premature to give a death toll. I can tell you that a number of people has been killed and the situation is still tense,” he added.
Simon Mwadkwon, a lawmaker representing the area in the federal House of Representatives in Nigeria’s capital Abuja, said at least 23 people had been killed in the two villages.
“Eight people were killed at Kankuru village and over 15 were killed at Kushen village,” he said, blaming the nomadic Fulanis.
But he had not seen the bodies of those killed, he said. No independent verification was available.
Jos and its environs have seen a wave of sectarian and communal clashes in recent years, leaving thousands dead.
The area has also been hit by gun and bomb attacks blamed on the Islamist group Boko Haram.