More than 70 New Zealand soldiers left Saturday on the country's 20th rotation of its forces in Afghanistan.

The first group of 36 soldiers left from Ohakea Air Force Base in the lower North Island and a second group of 41 left later from the Burnham Military Camp, near Christchurch in the South Island, Radio New Zealand reported.

Together they made up more than half the 140-strong contingent in the 20th rotation for the Provincial Reconstruction Team (PRT) working in Bamyan province.

The rest would go later this month, said the report.

It would be the first deployment to the war-torn country for 90 percent of the personnel, although they would be in "a relatively peaceful area," according to Radio New Zealand.

With the deaths of two PRT soldiers in three years, the New Zealand Defence Force (NZDF) has boosted its pre-deployment and in- Afghanistan training, Commanding Officer Lieutenant-Colonel Peter Hall told Radio New Zealand.

The focus of the new team was security and training the Afghan National Police, said Hall.

A third New Zealand PRT soldier died last week, but the NZDF has said the death was not combat related.

The PRT was deployed to Bamyan province in 2003 and the government has said it is committed to maintaining the force until 2014.

The province was the first to return to the control of Afghan forces last year.

Two New Zealand special forces soldiers were killed in attacks in Kabul last year, bringing the total NZDF losses in Afghanistan to five.