Armed police are searching a house in Armley after a member of the public reported seeing a man carrying a gun.
Police were called to an address on Hall Lane this afternoon and have now 'contained' the area.
The occupants are being spoken to by officers and a search is underway.
Part of the road has been closed and buses are running to diversionary routes.
Armley residents said they had seen armed response units arrive and park at the nearby Lidl supermarket.