Updated

Armed men killed a 42-year-old Red Cross staffer in the coastal Libyan city of Sirte, firing at his car after he left a meeting, the organization said.

Michael Greub, a Swiss national, died in the attack midday Wednesday, the International Committee of the Red Cross said in a statement on its website Thursday.

"We are devastated and outraged," said ICRC Director-General Yves Daccord. "Michael was a devoted humanitarian who spent many years of his life helping others."

Greub was in his car with his driver and another man, neither of whom were harmed, the Red Cross said.

Driver Ali Mohamed told The Associated Press that three masked attackers wearing civilian clothes stopped them at gunpoint at a checkpoint as they were on their way back from the meeting.

"They started shouting 'put your hands up,' and we put our hands up but they started shooting," he said. "We just crumpled to the car's floor but all of the firing was at the back seat where Michael was sitting."

Since the fall of dictator Moammar Gadhafi in 2011, there has been a spike in targeted killings with attacks on government employees, activists, clerics and security officials.

It was unclear who was behind Wednesday's attack, but Libyan military officers have said that hard-line Islamic militias including the extremist Ansar al-Shariah have stepped up their presence in recent months in Sirte, once Gadhafi's stronghold.

Greub worked for the ICRC for more than seven years, with assignments in Iraq, Sudan, Yemen and Gazi. He had been head of the organization's delegation in Misrata since March, the ICRC said.

The ICRC has had a permanent presence in Libya since 2011, providing humanitarian services for detainees, tracing missing persons and working with local organizations to help injured or displaced people.