(CNN) A humanitarian aid worker was shot and killed in Yemen on Saturday morning after an attack on his vehicle, the International Committee of the Red Cross (ICRC) said.

Hanna Lahoud was a staffer in charge of the ICRC's detention program in Yemen. The Lebanese national was on his way to visit a prison when a group of unknown armed men attacked the car he was in, the aid group said. Lahoud was immediately rushed to a hospital, where he died of his injuries.

A picture taken on April 21, 2018, shows the shattered rear window of the vehicle that was carrying Red Cross employee Hanna Lahoud, parked outside a hospital.

"We are all in shock," Robert Mardini, the ICRC's Middle East director, said in a statement. "Hanna was a young man full of life and was widely known and liked. Nothing can justify Hanna's murder and we are in deep mourning for our dear friend and colleague."

The colleagues Lahoud was traveling with were unharmed in the attack, which happened on the outskirts of the southwestern city of Taiz.

Humanitarian organizations in Yemen condemned the killing.

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