Tear gas was used as "a means to safely diffuse a volatile and dangerous situation" when protesters spilled onto an interstate highway in the heart of Philadelphia just before a curfew took effect, the city's police commissioner said.
Police also fired nonlethal bullets into the crowd and halted traffic during the Monday evening rush hour, and more than two dozen people were arrested during ongoing protests following George Floyd's death and other recent racially charged killings.
The crowds on Interstate 676 also led to the closure of the Benjamin Franklin Bridge, the main link from downtown Philadelphia to New Jersey suburbs. Some climbed a steep embankment and scaled a fence as police acted, while others moved to block the Benjamin Franklin Parkway, a grand thoroughfare leading from downtown to the city's imposing art museum.
The tear gas was used "when it became increasingly clear that other measures were ineffective" at dispersing the crowd, Police Commissioner Danielle Outlaw said.
"We will continue to evaluate the propriety of all applications of force, and make determinations as the circumstances of each unique situation dictate," Outlaw added.
The protests had mostly been peaceful before its chaotic conclusion Monday. It was among several staged across the country, inspired by the death last week of George Floyd, a black man who died after he was pinned by a white Minneapolis officer who put his knee on Floyd's neck.
The confrontation in Philadelphia came after the National Guard stationed vehicles outside City Hall and other downtown buildings, officials curtailed public transit, and city leaders put a curfew in effect for a third day Monday after a weekend of destruction that led to over 400 arrests.
