A man pulled the emergency brake on a Metro Line 1 train this morning at around 8:30am near Shanghai Circus World Station. The operation of Line 1 was delayed for about half an hour.

According to Shanghai Shentong Metro Groups, the train stopped for about 10 minutes before the driver was able to release the emergency brake. Because it was the morning rush hour, a large number of passengers were delayed, especially at stations between Shanghai Railway Station and Tonghe Xincun Station.

Witnesses said the man applied the brake because it was too hot in the carriage and the air-conditioning in the train was not working.

The operation of Line 1 resumed at 8:52am.

Metro police stepped in to look for the man who activated the brake. Despite there being witnesses, police haven’t yet identified him through security camera footage.

Metro operators said that since Line 1 is relatively old, there won't necessarily be cameras installed in each train carriage.