A section of northbound I-95 in Philadelphia has collapsed after a vehicle caught fire underneath the highway, Philadelphia officials said Sunday morning.

"We did have a collapse of 95 on the northbound side, and the southbound side is compromised by heavy fire," Derek Bowmer, battalion chief for the Philadelphia Fire Department, said during a news conference Sunday morning. "It looked like we had a lot of heat and heavy fire underneath the underpass."

Firefighters are still battling the blaze, Bowmer said.

Officials do not know whether anyone was injured or what kind of vehicle caught on fire.