NAIROBI (AFP) - An armed group stormed an upmarket shopping mall in the Kenyan capital Nairobi Saturday, sparking a fierce gunbattle, police said.

Police said they had surrounded the Westgate mall, which is popular with wealthy Kenyans and expatriates, and urged residents to stay away from the area.

"We have officers at the scene trying to get out the group shooting inside.

They have not been located," a senior police official told AFP.

"Officers are approaching the situation with caution because there are innocent civilians inside," he said.