UPDATED: July 8, 2016 12:25 PM

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DALLAS (CBSDFW.COM/KRLD) – Parts of downtown Dallas are still an active crime scene Friday morning after a dozen police officers were gunned down in the street Thursday night. Mayor Mike Rawlings and Chief David Brown with the Dallas Police Department said that they were still determining the size of the scene.

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“There are many people that work in the downtown area,” Rawlings said. “We ask them to stay away from that crime scene.”

Police are still conducting sweeps of the downtown area. Many parts of Dallas are now off-limits. The city put out a traffic map to help drivers better understand which blocks are completely closed to the public, and how cars are being diverted around the downtown scene.

(Image via City of Dallas, Dallas Police Dept.)

(credit: City of Dallas/Dallas Police Department)

The closed portion of Dallas is huge. All downtown streets in a 20-block area are shut off to the public. All streets, west to east, are closed from Houston Street to Griffin Street. From north to south, all roads from Ross Avenue to Jackson Street are shut down. The Commerce Street ramp from Stemmons Freeway into downtown is also closed.

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The downtown DART West End station remains closed as well.

The DART buses that regularly serve Central Business District West are being moved to Central Business District East. Those buses will board on Pacific Avenue, between Pearl Street and Olive Street.

Greyhound has also altered their schedule on Friday, temporarily moving operations to the Westmoreland terminal located at 627 North Westmoreland Road. This includes inbound buses as well, for travelers arriving to Dallas. The company added that any customers who choose to not travel on Friday will have their tickets refunded or reissued at no additional charge.

Dallas County Judge Clay Jenkins put out a news release early Friday saying that the George L. Allen Sr. Civil Courts Building, Dallas County Administration Building, Dallas County Records Building and the Old Red Museum are closed for the day. “If you don’t absolutely have to be in the western half of downtown today, Friday, please help us by staying out of the area,” said Jenkins.

The City of Dallas is updating information about Friday’s road closures online. Authorities added that several vehicles remain parked in this restricted area. It will take a few more hours before those cars can be released.

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