President Muhammadu Buhari has taken an early lead as votes are being counted in Nigeria’s general election. Buhari has won seven of Nigeria’s 36 states, while his rival Atiku Abubakar took two states and the capital Abuja.

The opposition People’s Democratic Party (PDP) have alleged irregularities in the vote and accused Buhari of manipulating the results.

Party chair Uche Secondus has criticised the initial tallies and accused the government of using “impeachments, manipulation, incarceration” to influence the outcome.

He said there had been an “attempt by the government and other agencies to manipulate the result”, but did not give any evidence.

Buhari, a member of the governing All Progressives Congress (APC) party, is seeking re-election but faces a strong challenge from Abubakar.

Each party says the other is working with the Independent National Electoral Commission (Inec) to influence the vote, which was initially scheduled for 16 February but delayed at the last minute.

Buhari has promised to build on his accomplishments in office so far, while Abubakar, a business tycoon, has accused the president of wasting his term.

Saturday’s general elections were marred by violence and voter intimidation. As many as 39 people have been killed in election violence, civil society groups said on Sunday.

The African Union observers have expressed concern about delays and logistical problems with Saturday’s elections but said it was free and fair.

“The 2019 elections took place in a generally peaceful environment,” said AU observer mission head Hailemariam Desalegn, the former prime minister of Ethiopia.

Final results are not expected until later in the week.