ABUJA, Nigeria (AP) — Frustrated Nigerians cast their ballots into the evening Saturday, hours after the official deadline for joining the voting line in Africa’s most populous nation after late starts and sporadic violence caused delays at polling stations. 

Election officials blamed the delays on logistical issues, though other observers pointed to the upheaval created by a redesigned currency that has left many unable to obtain bank notes. The cash shortage affected transport not only for voters but also election workers and police officers providing security.

There were fears of violence on Election Day, from Islamic militants in the north to separatists in the south. Voting was largely peaceful Saturday, though a dramatic scene unfolded in the megacity of Lagos in the mid-afternoon.

Associated Press journalists saw armed men pull up to the voting station in a minibus, fire shots in the air and snatch the presidential ballot box. The shots sent voters screaming and scattering for cover, and ballots strewn across the floor. 

And in the northeast state of Borno, at least five people including children, were wounded when Boko Haram extremists attacked voters in Gwoza town, local authorities said.

“The threat was neutralized by the troops of the Nigerian army who responded swiftly and chased the terrorists to the mountains,” said Abdu Umar, Borno’s state police commissioner.

Mahmood Yakubu, head of Nigeria’s election commission, said voting would continue late into the evening in places that had recorded violence but now have an adequate security presence.