Dutch authorities said 42,700 turkeys have been culled at a farm in the south of the country after a mild variant of the H7 bird flu strain was reported over the weekend.

"Today we got the test results and I can confirm that it was a low pathogenic strain," a spokesman for the Dutch ministry of economic affairs, agriculture and innovation said on Monday.

The virus was reported in the town of Kelpen-Oler in Limburg province, which borders Belgium and Germany.

Authorities immediately imposed a ban on transporting poultry, eggs, pigs and manure within 3 km of the farm but the spokesman said the halt would soon be lifted soon.

The H7 bird flu in its highly pathogenic form can kill large numbers of birds and can occasionally infect people, although it is rarely fatal in humans.

As a low-pathogenic variant can mutate into the high-pathogenic form, European regulations state that birds at a farm where either strain is detected must be culled.

Last year several cases of the low pathogenic bird flu strain were reported in the Netherlands.

The most devastating outbreak of H7N7 avian flu in the country was in 2003 and led to the culling of 30 million birds, about a third of the nation's poultry flock.