Witnesses have reported explosions and heavy gunfire at a hotel complex in the Kenyan capital Nairobi.
The suspected terror attack is unfolding at the complex, which houses a large hotel known as DusitD2, along with several banks and offices.
Police are said to be exchanging gunfire with the attackers in the operation.
Several cars have been seen on fire and people are being carried away from the scene.
Large plumes of smoke have also been seen rising from the area as scores of people have been reported injured.
Somali Islamist militant group al Shabaab has since said it is behind the attack and that its fighters were still inside the complex.
The incident comes on the third anniversary of the El Adde attack, which claimed the lives of several Kenyan soldiers in Somalia.
Police spokesman Charles Owino said officers had been deployed to the complex, including those from the country’s anti-terrorism unit.