New governors were being chosen for 28 of Nigeria's 36 states. [AP photo]

Millions of Nigerians voted Saturday to elect state governors but faced intimidation and violence in some cities amid heightened tensions following a disputed presidential election in Africa's most populous nation last month.

New governors were being chosen for 28 of Nigeria's 36 states as the political opposition continues to reject the victory of President-elect Bola Tinubu, who belongs to the ruling All Progressives Congress party.

By Saturday night, the counting of votes has started in most of the polling units across the country, though the winners in most of the states are not expected to be announced until Monday. Voting was postponed in a few locations, including in a Lagos town, over fear of attacks on electoral officials.

The performance of the Independent National Electoral Commission "has improved considerably compared to the Feb. 25 elections, but violence has been much more intense across the country," said Idayat Hassan, head of the Center for Democracy and Development, Nigeria's largest democracy-focused group. The group, which deployed more than 1,200 observers for the election, said violence in the election was more rampant in the southern region.

Local observer group YIAGA Africa said it found several instances in which voters were intimidated and prevented from voting unless they agreed to cast their ballots for certain political parties.

Among the places it listed was Lagos state, where the president-elect's party is seeking to retain the governor's office. The All Progressives Congress lost the state in last month's presidential and legislative elections.

"Security agencies should respond promptly to reports of voter intimidation and attack at polling units to accord citizens the opportunity to exercise their constitutional rights to vote," Samson Itodo, executive director of YIAGA Africa, said in a statement.

Allegations of vote-buying were also rampant. In Enugu, voters were intimidated and lured with as little as 200 naira ($0.43), according to Chidimma Igwe, who voted in the state.

"They (party representatives) will follow you right into the ballot box to see who you voted for. If you vote for PDP (one of the political parties), they will give you 200 naira," Igwe said.

Many Nigerians are struggling to survive in the aftermath of an ongoing currency swap program that created a cash shortage.

In Delta state, suspected thugs disrupted the voting in Ughelli and damaged election materials, according to resident Apkozie Emmanuel.

"Even the police were overwhelmed; they just stood aside," Emmanuel said.

A record 87.2 million people were registered to vote in the election, but observers reported low turnout Saturday, perhaps even lower than in the February elections. The 26.7% voter participation last month was the lowest in Nigerian history.

Although Nigeria is Africa's largest economy and one of its top oil producers, endemic corruption and poor governance have stifled the country's development. The Nigerian Constitution grants enormous powers to state governors, who are immune from prosecution while in office.

The prospect of holding the authority accorded governors make many politicians eager to get elected as one, the Center for Democracy and Development's Hassan said.

Yet polls have shown that many citizens do not have a high level of interest in the election or the performance of governors, a trend analysts said affects the level of accountability across the states.

"Even if we get the president right, everything else is against us - the people in the national assembly, the governors and the structural problems in terms of our constitution," said Ayisha Osori, a director at Open Society Foundations, a nonprofit organization.

Some voters also urged incoming governors to take steps to make life better for many living in poverty and unemployed.

In Lagos, trader Monica Obi lamented the high price of food items. "When you go to the market, you cannot buy one cup of rice," Obi said. "I have four children. I cannot feed them very well because the price is too much."