Gemfields Group said on Tuesday disruptions were possible at its largest ruby mine in Mozambique, after people torched buildings in villages nearby in escalating unrest linked to October’s disputed election.

Mozambique’s top court on Monday confirmed long-ruling party Frelimo’s victory in the election that has sparked protests by opposition groups that say the vote was rigged.

At least 130 people have been killed in clashes with police, according to the civil society monitoring group Plataforma Decide, and the operations of other foreign miners operating in Mozambique, including South32, have been affected.

Gemfields said in a statement that “groups associated with the illegal mining and trading of rubies have taken advantage of the political unrest”.

It said “instigators” had on Monday set fire to the police station in Namanhumbir, a village close to Gemfields’ Montepuez Ruby Mining Limitada (MRM) in the northern Cabo Delgado province.

An MRM office, a community centre and a community radio centre built by the company in Namanhumbir were also set ablaze.

“Based on the trajectory of the ongoing situation, there may be interruptions to MRM’s mining operations resulting from this unrest,” Gemfields said.

In another village near MRM’s operations, a water borehole was sabotaged, and in a third village people torched the police station, the residence of a local police commander and the administrative offices of Namanhumbir district.

MRM is 75% owned by Gemfields and employs about 1,400 people, the company’s website says.

Frelimo has been repeatedly accused by opponents and election observers of rigging votes, although it has denied those accusations. The electoral commission has not commented on allegations of fraud in this year’s election.