Two suicide bombers blew themselves up at the gates of Somalia's constituent assembly on Wednesday, killing themselves but with no other reported deaths, police said.

A Chicago man pleaded guilty Monday to attempting to provide support to a designated terrorist organization by traveling to Somalia to join the Shabab, prosecutors said.

Shaker Masri, 28, was born in Alabama and lived in Chicago's upscale Gold Coast neighborhood prior to his 2010 arrest, hours before he was scheduled to travel to Somalia.

A special assembly tasked with voting on a new constitution for war-torn Somalia convened for the first time Wednesday, as the corruption-riddled government approaches the end of its mandate next month.

Billed as the key to lifting anarchic Somalia out of two decades of civil war, the end of the transitional government comes as regional forces have wrested a series of key strongholds from al-Qaida linked Shebab insurgents.

Somalia's most powerful militant group publicly executed three of its members Sunday, saying the trio had spied on the militants for the U.S. and British intelligence agencies.

Al-Shabab said the three men were CIA and MI6 informants, and were the reason several drone attacks killed leaders from the group.

Somalia has made strides toward food security one year since its famine but the situation remains critical, the U.N. Food and Agriculture Organization said Friday.

"Today Somalia is on the path to recovery but the situation remains critical and continued aid is vital in order to preserve food security," the Rome-based organization said.

A grenade attack wounded four people in Kenya's Wajir border region with war-torn Somalia, police said Thursday, the latest in string of attacks in the volatile region.

Attackers in Wajir, some 100 kilometers from Somalia, hurled grenades into a restaurant and a shop late on Wednesday, said regional police chief Philip Tuimur.

A car bomb went off Monday in Somalia's volatile capital Mogadishu, killing a former trade minister and wounding six people nearby, officials said.

"The driver who died in the car bomb was Mohammed Abdinur Garweyne, he was a former trade minister and a lawmaker," said Mohamed Dhere, another lawmaker.

Four foreign aid workers kidnapped in Kenya's Dadaab refugee camp were released overnight in southern Somalia after a short gunfight, and were safe with the Kenyan army, officials said Monday.

"They are safe in our hands, they have been freed," Kenyan army spokesman Cyrus Oguna told Agence France Presse, adding that the two men and two women seized on Friday were released after a joint operation of Kenyan and Somali troops.

Gunmen killed 10 people and wounded dozens when they opened fire and hurled grenades into two churches in the eastern Kenyan town of Garissa on Sunday, the latest in a string of attacks, police said.

Gunmen burst into the churches in apparently coordinated attacks targeting worshippers as they held Sunday prayer services in Garissa, some 140 kilometers (85 miles) from the border with war-torn Somalia. The attackers later escaped.

Gunmen killed at least one person and kidnapped an aid worker in Kenya's Dadaab refugee camp, close to the border with war-torn Somalia, police sources and the Red Cross said Friday.