LIMA  - Communities in Peru's Ayacucho region say they will resume protests against the mining sector if the government of leftist President Pedro Castillo breaches what they call a signed agreement to shutter mines, local leaders told Reuters.

Prime Minister Mirtha Vasquez said last week that the government would not approve extensions for four mines over environmental concerns raised by local communities. On Wednesday authorities softened their public stance, saying the mines could seek permission to extend operations.

President Pedro Castillo came to power in July, with the backing of poor communities, who say the mines have deprived them of adequate water supplies and to whom he promised greater benefits.

The communities this month launched a wave of protests and told Reuters on Thursday they would resume their action unless the government stuck to the closure plans.

"The mines already have a closure plan and we want it to be carried out," said Julio Guillermo Gutierrez, leader of the Parinacochas People's Defense Front, one of the communities opposing the mines.

"The mining companies can request the extension of their operations if they want. But that is not what we want," Gutierrez said in a telephone conversation.

He said the local protests were only suspended and would be resumed if necessary.

Che Bernaola, a representative of the Ayacucho Sur Fighting Committee, told Reuters the group will demand that the closure of the mines be implemented.

"If the government does not comply with the signed agreement, we will activate the protest that had been suspended," he said. Most voters in Ayacucho and other mining areas voted for Castillo. "I doubt they will betray us now."

On Wednesday he released a letter in which he called on the region to join the defence of land and water resources that he said had been "poisoned" by mining.

The companies in question say they are complying with environmental standards, and that their operations do not pollute water supplies.

One of them is London-listed Hochschild Mining's, operator of the flagship Inmaculada silver project.

The threat of closure led the company's share price to lose over half of its value before it rebounded this week. On Thursday it was up strongly after the government's change of tone.

Hochschild said on Thursday its Inmaculada mine and another one in the Ayacucho region of Peru would continue to operate under current frameworks.

Peru is the world's No. 2 producer of copper and silver.

Under its law, all mines have a planned closure date, which can be modified if regulators allow it. The four mines in question have a closure schedule ranging from this year to 2025, the government says.