Staff at coronavirus laboratories in France have joined a strike, protesting against poor working conditions.

The CGT labour union told Reuters news agency that several hundred staff from coronavirus laboratories were taking part in the action, and that it was disrupting testing in some towns.

The union said the strike could drag on if laboratory bosses failed to deal with complaints over staff shortages and pay.

"We're overwhelmed," one laboratory nurse told Reuters. "We're exhausted, physically and mentally."

A technician told the news agency the pace of work was “relentless” and that workers were doing free overtime.

France has ramped up testing for coronavirus, and now conducts more than one million tests a week, according to officials.

But people have complained of long queues at testing centres and delays in receiving results.

A representative of employers in the sector said the strike was having a minimal impact on testing.

Like other countries in Europe, France has reported a surge in coronavirus cases in recent weeks.