HELP: NAME THIS GAME?

there was a game i used to play on my pc back in palestine.its a fps. the game had graphics very similar to quake. it was like an open city. there were shops were you can but guns.there were guards all over town. u could kill them all if can handle it. whenever you would shoot the shops would close down.i think the soldiers were red. when you would go into a restricted area they would attack you. there was also a sewer that you had to go in at some time in the game. sorry for the lack of details i tried google but it just gave stuff on earth quakes. PLEASE HELP .