Mozambique’s main opposition party on Saturday called for this week’s election to be annulled, accusing the government of breaching a peace deal by using violence and intimidation on voting day.

Partial results from Tuesday’s election show President Filipe Nyusi and his ruling Frelimo party headed for a major victory but the poll was marred by claims of fraud and irregularities.

Renamo accused Frelimo of violating a “cessation of hostilities agreement” under the August peace deal which states no party should “commit acts of violence and intimidation in the pursuit of political objectives”.

The party said some of its delegates were arrested after they caught poll organisers handing out more than one Frelimo ballot paper to voters.

“There were arbitrary arrests of agents … and voters who tried to complain about anything, ballot box stuffing, being unable to exercise the right to vote,” Renamo said in a statement.

It called for a cancellation of the vote and asked for “new elections that must be supervised by reputable entities”.

Government officials were not immediately available for comment.

With a third of the national vote counted, results on the National Election Commission’s website showed President Filipe Nyusi in the lead with 69 percent and Renamo leader Ossufo Momade with 25 percent.

The electoral commission is expected to announce the result of the provincial elections on Monday, and final results within 15 days of the vote.