You can enter the market after the gate has broken open. Go all the way down the street until you come across big red doors and gas cans next to them. Turn right just before the gas cans to find a brief case you can open with a VZ61 Machine gun in it. If you look closely, the gun looks similar to the "Scorpion" sub machine gun from Call Of Duty 4. This gun will make this level go by much faster.