Representatives from two of Nigeria’s three major political parties walked out from the National Collation Center in Abuja in protest against the irregularities they say were found in results announced so far, some blamed on glitches with technology heavily deployed in the vote.

Several party agents including those from the main opposition PDP and Peter Obi’s Labour Party alleged there were cases of over-voting and disparities between results announced from some states and what electoral officials uploaded on the election commission’s result portal.

“We are Nigerians and must defend our rights,” shouted the PDP’s Dino Melaye as he staged a one-man protest.N Nigeria’s electoral law allows party representatives or agents to raise concerns about results while they are being announced by the election commission.

Mahmood Yakubu, Nigeria’s election chief, said the results were authenticated by electoral officials at the voting unit, dismissing claims of irregularities. Each of the three frontrunners in Nigeria’s hotly contested presidential election claimed on Monday that they are on the path to victory as preliminary results trickled in two days after Africa’s most populous nation went to the polls.

Only four of Nigeria’s 36 states had officially announced results by midday Monday, with three of those going to ruling party candidate Bola Tinubu. The fourth was won by main opposition party candidate Atiku Abubakar. Also in the mix as a perceived frontrunner was Peter Obi with the Labour Party.