The Takfiri militants attacked the town of Dukku, 80 kilometers (50 miles) from the state capital city of Gombe, at about 11:30 a.m. (1030 GMT) on Saturday and opened fire randomly at voters in polling stations.
“They shot dead three people and injured two others,” said local resident Ibrahim Ahmad, adding that the assailants then killed a state assembly lawmaker and the local chief in the nearby village of Tilen.
Bala Akilu, another resident, confirmed the account, saying that several polling stations reopened after the attackers left.
“But others remained shut because voters had gone and were too afraid to return,” he added.
Earlier on Saturday, two people lost their lives in suspected Boko Haram attacks in the Gombe State villages of Birin Bolawa and Birin Fulani when the gunmen attacked polling stations there.
People in the oil-rich West African country turned out en masse to participate in the elections on Saturday, with the presidential vote being a close race between incumbent President Goodluck Jonathan and former military chief Muhammadu Buhari.
Nearly 360,000 police officers have been deployed across the violence-hit country to provide security for the polls, which had initially been set for February 14 but were postponed for fear of attacks by Boko Haram militants.
Boko Haram, whose name means “Western education is forbidden,” and controls parts of northeastern Nigeria, has vowed to disrupt the polls.
The Takfiris have claimed responsibility for a number of deadly shooting attacks and bombings in various parts of Nigeria since the beginning of their activities in 2009, which have so far left over 13,000 people dead and 1.5 million displaced.