UPDATE: Service Resumes After Morning Blue Line Disruption

Update, 11:37 a.m. CTA reporting "trains are now moving and normal service is being restored. Allow extra travel time."

Update, 11:27 a.m. Previously closed, Des Plaines at Jackson has re-opened to vehicle traffic. CTA shuttles have been taking westbound commuters from the Harlem stop to Forest Park.

"They didn't say nothing," said Chicago resident Francine Baker, 37, en route to Maywood. "They just told us 'Get off, we're not going that far.'" 

At the Forest Park stop, dozens of commuters piled out of the CTA shuttles, but police tape prevented them reaching their cars in the parking lot. 

Original post: Transit service on a portion of the CTA Blue Line has been halted as authorities investigate an 'unattended package,' found at the Forest Park Transit Center. 

According to the CTA website, "trains are operating only between O'Hare and Harlem/Congress at this time. Shuttle buses are available to provide connecting service between Harlem/Congress and Forest Park."

CTA spokeswoman Wanda Taylor told the Tribune's Chicago Breaking News wesbite an unattended package was reported at about 9:30 a.m.