Gunmen attacked a major hotel in the centre of the Somali capital Sunday, according to an AFP reporter, who heard at least two loud explosions followed by intense gunfire.
There was no immediate confirmation who was carrying out the attack, as fighting continued in the Sahafi hotel, which is popular with government employees and businessmen, and is situated near the major K4 roundabout.
Al-Qaeda affiliated Shebab insurgents have previously carried out a string of attacks on hotels in Mogadishu.
The Islamists, who are fighting to overthrow the internationally-backed government in Mogadishu, have frequently used car bombs driven by suicide bombers to break into a complex or a building, with more attackers following on foot.
Like other international hotels in Mogadishu, the Sahafi is heavily fortified.
It was the site of the kidnapping of two French security agents in 2009, one of whom later escaped while the other was killed by the Shebab during a failed rescue attempt.
Shebab attacks seek to counter claims that they are close to defeat after losing territory to the 22,000-strong African Union force and Somali government troops, as well as regular US drone strikes against their leaders.
The militants have also carried out a string of revenge strikes in neighbouring countries.