Seven Bangladeshi sailors, held hostage by Somali pirates for almost four years, finally returned home Thursday, saying it was "unbelievable" to be alive and describing their ordeal as "like hell."

The sailors, who had been held in dire conditions and suffered beatings, flew into the Bangladeshi capital after the foreign ministry said they were freed last week after lengthy negotiations. 

At least 12 people died in heavy fighting between rival militia in central Somalia, elders said Wednesday, the latest surge of violence amid warnings of a worsening humanitarian crisis.

Fighting in the Galgadud region broke out Tuesday, despite local governor Hussein Ali Weheliye calling on "both sides to show restraint to stop the senseless killing going".

Thousands of children in war-torn Somalia are facing death or disability due to an outbreak of highly contagious measles, the United Nations said Tuesday.

Recent rates of infection are four times higher than the same time last year, and a vaccination campaign must be "urgently conducted to prevent thousands of avoidable deaths", the U.N. children's agency UNICEF and the  World Health Organization (WHO) warned in a joint statement.

Thousands of children in war-torn Somalia are facing death or disability due to an outbreak of highly contagious measles, the United Nations said Tuesday.

Recent rates of infection are four times higher than the same time last year, and a vaccination campaign must be "urgently conducted to prevent thousands of avoidable deaths", the U.N. children's agency UNICEF and the World Health Organization (WHO) warned in a joint statement.

Somali and African Union troops have carried out a major security swoop in Mogadishu, arresting dozens of suspected Shebab militants believed to have infiltrated the capital, the government said Saturday.

The security operation, which began on Monday, comes in the wake of a string of Shebab car bombings and suicide commando attacks against high profile targets in the city, including the heavily-fortified office of the country's internationally-backed president as well as the national parliament.

Eleven sailors mostly from Asia held hostage for almost four years by Somali pirates have been freed and are safe on their way to Kenya, mediators who helped secure their release said Saturday.

The sailors, who had been held in dire conditions and suffered beatings and torture, included seven men from Bangladesh, one Indian, one Iranian, and two from Sri Lanka.

Three Kenyan aid workers held hostage by pirates in northern Somalia for close to two years have been freed unharmed, their employer said Friday.

International Aid Services (IAS) is "overjoyed to announce that three of its staff members who were kidnapped in Somalia over 22 months ago have been released and are safe and well," the organization said in a statement.

Sixty migrants from Somalia and Ethiopia and two Yemeni crew members drowned last weekend in the worst such tragedy off the coast of Yemen this year, the U.N. said Friday.

"The tragedy is the largest single loss of life of migrants and refugees attempting to reach Yemen via the Red Sea and the Gulf of Aden this year," Adrian Edwards, spokesman for the UN's refugee agency, told reporters in Geneva.

Turning a new page in their troubled ties, President Barack Obama is set to name the first American ambassador to Somalia since the civil war erupted over 20 years ago, a U.S. diplomat said Tuesday.

"As a reflection both of our deepening relationship with the country and of our faith that better times are ahead, the president will propose the first U.S. ambassador to Somalia in more than two decades," Undersecretary Wendy Sherman told a U.S. think tank.

A Canadian was convicted Friday of trying to join Somalia's Shebab militants, marking the first time Ottawa has brought charges of attempting to participate in terrorist activity.

Mohamed Hersi, 28, was arrested at Toronto's airport in March 2011 as he was about to leave for Cairo.