An aid worker with the UN's World Food Program (WFP) was killed in the capital Mogadishu Thursday, two days after four foreign aid workers were kidnapped and safely released in a different part of the country, Radio Garowe reports.

Ahmed Hussein "Gesey" was killed inside his car by two unidentified gunmen, whom witnesses described as young men, who immediately fled away.

"The shooting happened near his home in Yaaqshiid district," said a witness, who added that the victim answered his mobile moments before he was fatally shot in the head.

The late Ahmed Hussein was the WFP's local food distribution head in Mogadishu. Residents said he recently helped distribute food aid to internally displaced peoples camps in Elasha Biyaha, in the southern outskirts of Mogadishu.

He was planning to travel to the Jubba regions to help distribute food, said a relative named Ahmed Abdinur.

"The victim was killed by evil hands and I call on them to stop attacking aid workers," Mr. Abdinur added.

No group has claimed responsibility for the killing.

In Bakool region, Al Shabaab insurgents reportedly "rescued" four UN aid workers earlier this week after they were held hostage for a few hours.

Somalia is considered a dangerous country for aid workers to operate, with many fatal shootings since 2007.