Move along this street and gun down the dog on the other side of the fence. It's better to shoot him now than break his neck in a minute. Turn to the left and check the corner right after the dog. Kill the militiaman here to spoil his ambush. Then take cover behind a dumpster and fire on the militiamen on the rooftops in front of you.

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Turn to the left and clear out the 2 guys on the street. Then curve around up the narrow staircase. A militiaman will pop out with a machine gun in the window ahead. Kill him and get ready to take this street. Get into the house on the left and use the exit to fire on the guys in front of you. Make sure that no one gets behind you though. If you take fire, then spin around and take them out.
Take out the guy on the makeshift bridge above you. Then shoot the 2 guys on the street. After that, you need to kill the sniper across from you, the machine gunner above him, and the last gunman in the stairwell to the left of the sniper. Just do methodical and simple shots. Charge forward and up the next set of stairs. Shoot the guy at the top of the steps by the little wall. Use this wall for cover and fire on the large group of militiamen counterattacking. Once you've thinned them out, clear the large house to the right. There should be about 4 guys in it. Clear out the house to the left too. Then go up the street and watch for more men on the rooftops.
Get up onto the rooftop to the left. You can use the stairs on the outside or the ladder inside. Run to the back corner and get behind the cinder blocks and the wall. Focus on taking out the 3 men on the high rooftops in front of you. Then work your way to the left and clear out all the gunmen. Go across the makeshift bridges and kill the few remaining guys on the other side. Watch the rooftops to the left for another 2 guys. Kill them and go up one more set of stairs. We're almost done with this chaos.
Kill the men on the rooftop, but watch out for Rojas. We can't shoot him. Charge forward and curve to the left to finally watch Rojas' capture.