Washington (AFP) - The United States is deploying "a few dozen" troops to Somalia to assist the national army and conduct unspecified security operations, a US military spokeswoman said Saturday.

The soldiers from the 101st Airborne Division, a light infantry unit trained for air assaults, will mainly train and equip Somalia's army "to better fight Al-Shabab," an Al-Qaeda linked extremist group, the spokeswoman for the US Africa Command based in Germany, Samantha Reho, told AFP.

They will also conduct "security force assistance," she said, confirming a report by Voice of America.

"For operational security issues, we will not discuss specifics of military efforts nor speculate on potential future activities or operations," she said, declining to say precisely how many troops were being sent.

Somalia's fragile central government is still propped up by the international community and a 22,000-strong African Union peacekeeping force after nearly three decades of civil war and anarchy.

While Shabab militants have lost large swaths of territory and were forced out of Mogadishu by African Union troops in 2011, they continue to strike in the capital and countryside.

They have threatened a "merciless" war against the new administration of President Mohamed Abdullahi Mohamed, a dual US-Somali citizen who goes by the nickname Farmajo. He took office in February.

The 101st Airborne Division has been extensively used in US-led military campaigns in Iraq and Afghanistan.

The United States' most notorious military operation in Somalia was in 1993, when an ill-fated attempt to snatch militia leaders led to two Black Hawk helicopters being shot down in Mogadishu. A chaotic rescue was mounted, resulting in hundreds of deaths, including those of 18 US soldiers. The incident was made famous in the book and the movie "Black Hawk Down."

The US military spokeswoman noted that US forces have been in Somalia since 1993, helping the Somali government on security concerns.