A gunman killed two Yemenis working for the International Committee of the Red Cross north of the capital Sanaa on Wednesday.

A gunman killed two Yemenis working for the International Committee of the Red Cross north of the capital Sanaa on Wednesday, a spokeswoman for the humanitarian organization said.

The pair were travelling with two colleagues in two vehicles "clearly" marked with the Red Cross emblem when they were stopped in Amran province by a gunman who opened fire at the vehicles, the ICRC's Yemen spokeswoman Rima Kamal said.

"One of our colleagues passed away on the spot while another sustained critical injuries and was transferred to an MSF (Doctors Without Borders) hospital... where he passed away shortly after," she said.

The other two were unharmed, Kamal added.

The head of the ICRC delegation in Yemen, Antoine Grand, said the victims were a field officer and a driver.

ICRC spokeswoman in Geneva Sitara Jabeen told AFP that "after the incident, the Red Cross stopped all movements in the country for the time being."

The ICRC said it was not immediately clear who carried out the attack, noting that there had been a number of security incidents involving the organization in recent months.

On August 25, the ICRC said it had suspended its operations in Yemen's second city Aden after gunmen robbed its main office while holding staff at gunpoint.