Plateau has for years suffered tit-for-tat violence between nomadic herders and farmers over land and water that has taken on a wider ethnic, political and religious dimension.
In June, herders were blamed for attacks on 11 villages in Barakin Ladi which killed more than 200 people from farming communities.
But Terna said only that "unknown gunmen" were blamed for both attacks and more security personnel had been deployed to the affected areas.
State governor Simon Lalong condemned both incidents and warned the affected communities not to mount reprisal attacks.
That "will be playing to the script of these perpetrators whose ultimate aim is to return the state to the dark era of bloodletting," he added.
The International Crisis Group think-tank in July warned the resource conflict was now an even greater security threat to Nigeria's national security than Boko Haram.
At least 1,500 people have been killed in central states since September last year, most of them in the first six months of 2018.
More than 300,000 had been made homeless, it added, warning that the violence had the potential to destabilise the country and disrupt elections scheduled for February 2019.