Two New Zealanders were among a team of Red Cross staff caught up in a failed bombing attempt in Afghanistan.

The New Zealand Red Cross said two of its members were shaken but unharmed when an explosive on a motorcycle failed to detonate properly outside a hospital in Kandahar yesterday.

The International Committee of the Red Cross (ICRC) said staff were arriving at the hospital to begin their shift when "a small explosive went off in the grounds of the Mirwais Hospital".

Only the fuse detonated, causing minor injuries to two ICRC staff from flying gravel.

The attack happened outside the entrance to the hospital, about 4pm (local time).

The two New Zealand aid workers were not physically harmed, although they were shaken.

A third, also based at the hospital, was on leave.

As a result of the attack, the ICRC team in Mirwais Hospital was immediately evacuated to the ICRC's compound.

ICRC hospital activities had been suspended for three days.

But, a spokesman said that ICRC activities in Kandahar, not related to the work in Mirwais, were continuing.

Full security measures had been put in place.

"This incident again highlights the growing violence against healthcare workers, facilities and beneficiaries; remaining one of the most serious humanitarian challenges in the world today. And yet it frequently goes unrecognised," the Red Cross said.

"A single act of violence that damages a hospital or kills healthcare workers has a knock-on effect, depriving many patients of treatment they would otherwise have received from the facility or workers in question."

- © Fairfax NZ News