A large number of dirt bikers rode through Philadelphia on Sunday, reportedly to mark the fourth anniversary of the shooting death of a popular local dirt bike rider.

6ABC reported that the ride included several hundred riders, and police said the event was in memory of Kyrell Tyler, a stunt rider with a large following on Instagram who was known online as "Dirt Bike Rell." Tyler was found shot to death in a car in Southwest Philadelphia on this date in 2014. He was 23.

At his funeral, Tyler's godmother, Sheila Alston, described him as "fearless."

"He rode on the streets, on the expressway, on the dirt, wherever he could ride," she said. Tyler's funeral was followed by a similar ride through the city.

Police said there were several groups of riders throughout the city on Sunday, and that officers were monitoring the ride.

Later on Sunday evening, they said about 20 people had been arrested in connection with the event. Dirt bikes are illegal in Philadelphia on most streets, but police did not specify what anyone had been charged with. Police said they had also confiscated 30 dirt bikes and two guns.