Gemfields has halted operations at its Montepuez ruby mine, in Mozambique, and evacuated the site after an attack on a nearby facility by rebels.
Thousands of people have died since the start of the brutal Cabo Delgado conflict in October 2017, aimed at establishing an Islamic state in Mozambique.
Gemfields said in a statement that “an attack attributed to insurgent activity has been reported at the neighbouring ruby mine belonging to Gemrock, which lies approximately 12km south-east of the operations of Montepuez Ruby Mining.”
The London-based miner operates and owns 75 per cent of Montepuez Ruby Mining (MRM).
It said: “Gemfields and MRM hold the health and safety of their employees and contractors as their highest priority and remain in regular contact with government authorities.”
The company said it was still trying to verify details of the attack, last Thursday (20 October).
In August it said operations would be continuing, with increased vigilance, despite an attack in the vicinity as party of an Islamic State-linked insurgency.