Security forces repelled an attack by Islamic extremists on a coalition center in northeastern Nigeria and several election officials elsewhere were kidnapped as results trickled in Sunday from the gubernatorial vote.

Meanwhile, the incumbent governor in the battleground state of Lagos appeared to have secured reelection, though results from more than two-thirds of the states were still being counted. Festus Okoye, a spokesman for Nigeria’s Independent National Electoral Commission, said Sunday it had received reports of violence and was reviewing them. Nigeria’s election laws grant the electoral body the power to void the outcome of an election in certain circumstances.

“Some of our staff were abducted, some were harassed, some were intimidated, some were hospitalized and in one case killed,” Okoye said.

Twenty-eight of Nigeria’s 36 states held elections for new governors on Saturday while state lawmakers were also elected for nearly 1,000 constituencies. Nigeria’s constitution grants governors both enormous powers and immunity from any form of prosecution while in office, making them very influential both in their states and at the federal level.

Saturday’s elections were held as the political opposition continues to reject the recent victory of President-elect Bola Tinubu, who belongs to the ruling All Progressives Congress party. In the northeastern Borno state, Islamic State-backed extremist rebels attempted to disrupt the collation of results on Sunday but were repelled by security forces who killed many of them, local officials and residents said.

Babangida Ajiri, head of a local security outfit collaborating with the military, said at least 40 of the rebels were killed with their arms recovered. “They wanted to surround the village, but the troops engaged professionally and thwarted their mission,” said Ajiri. “It was during the early morning search that we discovered most of the bodies of the killed terrorists.”

The ruling All Progressives Congress’ Babajide Sanwo-Olu had won 19 of the 20 council areas in Lagos state, defeating Gbadebo Rhodes-Vivour of the Labour Party. He immediately rejected the outcome, alleging that their supporters were intimidated and that the result was manipulated.