A suspected Naga rebel opened fire at a police station packed with voters on a tense election day Saturday in northeast India, killing four people before he was shot dead, police said.
The gunman lined up with other voters outside but pulled out a revolver once he entered the building and began shooting indiscriminately, said Priyo Kumar Singh, police superintendent for Chandel district in the state of Manipur.
Dozens of militant groups are active in northeast India, and the Manipur's state assembly elections were already tense with the threat of violence, after seven militant groups banded together against the governing Congress Party.
Some 35,000 security personnel were deployed alongside armed police at more than 2,300 voting stations statewide.
Police said the gunman was a suspected member of the National Socialist Council of Nagaland, which has been fighting for decades for an independent homeland. About 2 million Nagas live in northeast India bordering Myanmar.
He killed two poll workers, a paramilitary officer and a woman before another paramilitary officer shot him dead. The station is in Thangpi, about 40 miles (70 kilometers) south of the state capital of Imphal.
"I can say this looks like a suicide mission," Singh said. "It is difficult to understand why only one militant would come to attack."
Press Trust of India said several suspected bombs were also found and defused before polling started. PTI did not cite sources for the report, and it was not clear who may have planted the alleged bombs.
The dozens of militant groups in northeast India seek independence or more autonomy for different ethnic, cultural or political groups. Most accuse the Indian government of neglecting and discriminating against the region while also exploiting its rich natural resources.