Police in Somalia say that militants wearing suicide vests and carrying guns and grenades have attacked the presidential palace.
Police Capt Mohamed Hussein said they began the attack with a car bomb, and then tried to fight their way into the presidential palace as guards returned fire.
Casualty figures were not immediately known.
A second police officer, Ali Hassan, said a second blast was heard during the attack.
The heavily guarded presidential palace is the residence of the country's president, prime minister and speaker of parliament.
An al-Qaida-linked group called al-Shabab has been waging war in Somalia for years.