Peter Gyedeng, a member of Plateau State's parliament, said over 200 of his constituents died in the attack.
"Over 200 innocent citizens of my constituency were killed...this is barbaric and evil. This is happening even when we have security all over the state," Gyedeng told reporters in Jos, the state capital.
The lawmaker alleged "genocide and ethnic cleansing" against his constituents.
The attacks, which started on Saturday, continued on Monday in another area of the state, despite a dawn-to-dusk curfew imposed by the government.
Local police on Sunday confirmed only 86 people were killed and six others severely wounded. Meanwhile, 50 houses, two cars, and 15 motorcycles were razed, the police added. However, residents said more than 140 bodies were buried during a mass funeral on the same day.
More than 11 villages were targeted by the gunmen during these coordinated attacks, which mostly affected Razat, Nekan, Ruku, Nyarr, Kufang, Kura and Gana-Ropp villages of Gashish District in Barkin Ladi area of Plateau, Terna Tyopev, the spokesman for Plateau police, said.
The local Vanguard Newspaper on Wednesday reported that Ruku Village recorded more deaths in the attack, with at least 47 victims.
President of Nigeria's Senate Bukola Saraki on Wednesday arrived in the city of Jos to commiserate with Governor Simon Lalong and families of the victims.
Saraki's visit was also to do an on-the-spot assessment of the carnage.
On Tuesday, Nigerian president Muhammadu Buhari was also in the city to mourn the victims. Buhari's condolence visit was preceded by that of Vice President Yemi Osinbajo who led a federal government delegation to Plateau following the attacks.
Plateau State is located in Nigeria's middle belt where the Muslim-dominated north and the Christian-majority south meet.
There had been a long time strife in the central state between indigenous groups, mostly Christian or animist, and migrants and settlers from the Hausa-speaking Muslim over the control of fertile farmlands.
Earlier in the week, one regional head of a local cattle breeders group had opined that those who carried out the attacks in Plateau might be on a revenge mission.
Danladi Ciroma, the head of the Miyetti Allah Cattle Breeders Association of Nigeria (MACBAN) in the north-central region, said there had been recent reports of cow rustling and destruction of farms between local farmers and herdsmen.
"The people carrying out these criminal activities are well known to the communities but the communities are hiding them," Ciroma said in a statement.
This incident was not the first herdsmen-farmers conflict in the most populous African country, whose estimated nearly 200 million people are divided into at least 200 distinct ethnic groups and about evenly split between Muslims and Christians.
On March 7, 2010, members of local Muslim and Christian communities fought each other in revenge for previous killings.
In November 2008, clashes between Muslim and Christian gangs triggered by a disputed local government election killed hundreds of people in Jos and rendered thousands of people homeless.
According to media reports, hundreds of people died in clashes in the town of Yelwa in Plateau State in 2004, while in September 2001, ethnic and religious rioting in Jos had killed at least 915 people, according to official statistics.
On the other hand, Plateau has witnessed some bomb blasts, too, apart from the constant rifts between local farmers and herdsmen, with many, especially women and children, losing their lives.
The herders, pressured with the effects of climate change and others, are forced southward into the farming communities in search of better resources of grazing.
The threats posed by the fighting between herders and farmers as provided by some accounts have been more serious than those from Nigeria's Boko Haram extremist insurgency.
The conflict in the region has weighed upon the government and other political forces as general elections approach next year.