A car bomb has exploded at the gates of Somalia's presidential palace, followed by an attack by gunmen, police in Mogadishu say.
A fierce gunfight is now said to be underway inside the compound.
President Hassan Sheikh Mohamud has called the UN envoy to Somalia to say he was not harmed during the attack, envoy Nick Kay has tweeted.
The UN-backed government is battling al-Qaeda-linked group al-Shabab for control of the country.
Senior police officer Abdikadir Ahmed told the Reuters news agency the fighting was going on in the house of a military commander within the presidential compound, near the palace.
"The car bomb hit and exploded and other al-Shabab cars with armed men drove inside the palace, and heavy fighting is still going on," he said.
Mr Kay said: "Sadly some lives lost. I condemn strongly this terrorism."
