At least 36 people have died and dozens of houses have been burned in religious clashes central Nigeria over the past week.
The military said on Saturday that the latest casualties were in addition to at least 23 people killed in attacks in the volatile region on March 20 and 21.
Al Jazeera's Mohammed Adow, reporting from Lagos, said that there had been weeks of tension between Muslims and Christians in the lead-up to the attacks.
"The military and the government are saying they are not taking any chances and they are beefing up security to ensure that there are no further attacks," Adow said.
Violence since Monday has seen ethnic Fulani Muslims raid Christian villages in Plateau state, an area where thousands have been killed or displaced in recent years in a cycle of attacks and reprisals.
Plateau is in the so-called Middle Belt region which divides the mainly Christian south and mostly Muslim north of Africa's most populous nation.
The latest attack occurred late on Thursday in the Barkin Ladi area, Lieutenant Jude Akpa, a security task force spokesman, said.
"Unknown gunmen suspected to be Fulanis attacked and killed nine persons there and three were injured," he said.
Cattle herdsmen blamed
Emmanuel Lohman, a government official in Barkin Ladi, said that the assailants, armed with assault rifles, struck a village called Ratas and opened fire in the night while many there were sleeping.
Witnesses said that the shooting lasted for almost two hours before the attackers fled.
The Christian villagers there, who farm the fertile soils of Plateau, blamed nomadic Hausa-Fulani cattle herdsmen for the attack.
Such attacks remain common as Christian farmers clash with the herdsmen over land and grazing rights.
Other attacks are often rooted in disputes over political and economic power in the region.
Muhammadu Nura, the state secretary of a cattle breeders association, said that Hausa-Fulani people had been killed in "reprisals", but denied herders were involved the attacks.
Police officers dead
An attack and subsequent shootout in the Bokkos area killed 25 people on Wednesday.
Akpa said that the attackers were believed to be Fulanis and two police officers were wounded by gunfire.
"We had 19 persons killed," he said of the initial attack. "We sent in reinforcements. Six of the attackers were killed."
Violence in the Riyom district left at least two police officers dead when their patrol was ambushed on Monday.
Akpa said that at least 30 houses were burnt in the area on March 23, but he could not confirm any deaths.
Plateau has experienced waves violence involving the Fulani ethnic group and Christian Beroms, who see themselves as the indigenes of the state.
The Boko Haram group has carried out bombings in Jos, the capital of Plateau, as part of its insurgency in central and northern Nigeria.