Philadelphia Police are doubling up patrols following the killing of five Dallas police officers Thursday night.

Police Commissioner Richard Ross ordered the city's 6,600 officers to patrol in pairs Thursday night, according to Newsworks. It is unclear how long the policy will last. Philadelphia officers typically patrol solo.

Snipers shot 12 police officers in Dallas Thursday night during a Black Lives Matter demonstration protesting the police killings of black men earlier this week. One of four suspects told Dallas Police he was upset about Black Lives Matter, the recent shootings and wanted to kill white people.

Philadelphia Police spokesman Lt. John Stanford told Newsworks that he felt helpless after learning of the Dallas shootings.

"I don't really know what you do to prevent that," he said. "It's a tough time for many communities. It's a tough time for law enforcement. When there's a police-involved shooting that happened 10,000 miles across the country, it still has an impact in Philadelphia, just as the events in Dallas have an impact in Philadelphia. I don't know how to prevent these things, but they don't represent every police officer, and they don't represent every protester."

Philadelphia police routinely handle large demonstrations, including many that have protested police conduct both in Philadelphia and across the nation. Demonstrators have marched in Philadelphia the last two nights, voicing their anger over the deaths of Alton Sterling in Louisiana and Philando Castile in Minnesota.

Such protests occasionally have resulted in a handful of arrests, but mostly have preceded without any major incidents by protesters or police.

Whether the Dallas shootings prompt Philadelphia Police to alter the way they handle mass demonstrations remains to be seen. Police did not immediately respond to a PhillyVoice request for comment.

Tens of thousands of people are expected to protest during the Democratic National Convention here later this month. Some protestors have received permits, but others say they will proceed with or without them.

Speaking at a press conference Thursday afternoon, Ross said police would "not make any predetermined ideas or notions" about how they would handle the protests. He stressed that such demonstrations require police to be fluid, pointing the varied protests police have overseen during the last 18 months.

"We are prepared to deal with just about anything that comes up," Ross said. "Again, we're not new to conventions and we're not new to large-scale events, which is critical to point out. ... When you deal with large-scale protests and events, you have to be fluid. We will not be boxed into events about what we will and will not do. We'll make those determinations at those times."

Ross said police will be outfitted in their standard uniforms and carrying standard equipment during the DNC.