A stampede at a rap concert on a beach has killed at least 33 people, including 11 children, in the Guinean capital Conakry, hospital officials said.

The government declared a week of national mourning after what it called a "tragic drama" on Tuesday in the capital's northern Ratoma suburb where popular Guinean rap group Instinct Killers was playing among other artists.

The concert was being held to mark the end of Ramadan.

Medics took dozens of bodies to a hospital morgue at Donka, a hospital official told the AFP news agency.

The president's office said in a statement it was "shocked by the tragic drama caused by mass movements at a cultural event".

An investigation has been launched to determine what caused the tragedy. The official in charge of organising such events was suspended.