SEPTA riders are dealing with delays after all of the Regional Rail lines were suspended on Thursday afternoon, according to the transit agency.

Fire department activity in Center City caused the stoppage, SEPTA explained.

A spokesperson with SEPTA told NBC10 that the trains were stopped as a precaution because there was a burning type of smell in the tunnel.

AS of 7:30 p.m. on Thursday, the Regional Rail lines are moving again but there are still significant delays.

This is a developing story. Check back here for updates.