Shipments from four mines that produce about half of Peru’s copper – Freeport-McMoRan Inc’s Cerro Verde deposit, MMG Ltd’s Las Bambas, Glencore PLC’s Antapaccay and Hudbay Mineral’s Constancia – had been suspended for nearly three weeks due to the unrest.

The protests started after the government issued a construction permit for a new mine in the region – Southern Copper Corp’s $1.4 billion Tia Maria project – that local farmers have opposed for nearly a decade.

But the government suspended the permit for the project late on Friday while authorities evaluate its legality.

By Saturday, protesters were no longer blocking a minerals railway and roads used to transport concentrates, allowing Matarani to resume normal operations, said Julia Davila, communications director for port operator Tisur.

Domingo Drago, the vice president of corporate affairs for MMG, also said that Las Bambas and the three other mines that use Matarani were able to resume exports on Saturday.

Some protests against Tia Maria have continued in the southern Peruvian region of Arequipa, with local residents demanding the full annulment of the construction permit, according to local media on Tuesday.