Police in Zimbabwe have arrested 41 election monitors for allegedly trying to disrupt the voting process.

Those being held, from civil society groups, were allegedly co-ordinating the release of results from Wednesday's general election, police say.

They are being charged with breaking electoral law, their lawyers say.

Civil society groups have tried to do their own vote count to compare results with the official tally in light of disputes over past election results.

Officers carried out a series of raids and arrests in the capital, Harare, including at a hotel and offices of the Zimbabwe Election Support Network and the Elections Resource Centre, where the 41 worked.

Initially, lawyers said they had received disturbing distress calls from clients, adding that they did not know where the police had taken them. But they were later granted access to their clients.

Police spokesman Paul Nyathi has said that 38 laptop computers and 93 phones were seized from the offices. He added that "any form of chaos" during the election would be "severely" dealt with.

On Wednesday, Zimbabweans went to the polls to elect a president, members of parliament and local councillors.

The arrests came as voting was extended to a second day in three provinces of the country due to delays on Wednesday.

In Harare, only a quarter of polling stations opened on time because of problems with ballot papers. In some areas, ballot papers ran out, forcing voters to wait late into the night.

The electoral commission blamed last-minute court challenges for the late arrival of council election ballot papers.

Meanwhile, leader of the main opposition Citizens Coalition for Change (CCC) Nelson Chamisa accused the authorities of "voter suppression".

Vote counting is under way and election officials have five days to declare the results of the presidential election.

In 2018, Mr Chamisa was unsuccessful in his legal bid to overturn the results from that year's election, which he described as a "coup against [the people's] will".

Official results showed that he took a 44% share of the vote in the presidential election - the incumbent, Emmerson Mnangagwa, won with 51%.

This week's vote was the second time the two men have faced each other in a race for the top job.