Riders last night were forced off a No. 7 train that filled with smoke from a track fire near Grand Central Terminal Monday night, officials said.

Passengers on the Queens-bound train were stuck inside a smoky train car for about 20 minutes before 11 p.m. As the train rolled into the tunnel out of Grand Central, the train operator “heard a pop” and the tunnel filled with smoke, according to MTA spokeswoman Judie Glave.

The power was killed, though fans in the train were still running, Glave said.

Riders posted pictures of the ordeal on social media that showed passengers shielding their faces from the smoke.

The FDNY, which responded with 60 firefighters, said some garbage on the tracks started a small fire. The MTA is investigating the incident.

The train was eventually brought back to Grand Central to let passengers off. Officials did not know how many people were on the train at the time. There were no reported injuries, according to the FDNY.