A train on the Wuhan-Guangzhou high-speed line, the G6009, was an hour late on Wednesday due to a fault in the automatic protection system, just one day after three trains on the same line were delayed by a smoking passenger, the News Express reported.

Technical workers were quickly sent to the scene, and other high-speed trains traveled on schedule that day.

A day earlier, three trains on the line were delayed due to alarms apparently set off by a smoker on train G1048, which was scheduled to leave for Wuhan at 2:50 pm Tuesday.

The Wuhan-Guangzhou high-speed trains installed an automatic protection system to ensure safety when emergency happens. Smoking on the high-speed train is one of the actions that can cause a train to stop.

Traditional trains allow smoking in toilets and in the covered spaces connecting train cars, but not in air-conditioned areas. Because high-speed trains are fully air-conditioned, smoking is banned on all bullet trains.

"I can't smoke on the train? Oh, it's just like when I was on a plane," an unnamed passenger said.

According to media reports, the slack season and high price - $109 for first-class seats and $68 for normal seats – are leading to fewer passengers on the Wuhan-Guangzhou high-speed trains. The high-speed rail service between Wuhan and Guangzhou began on December 26, reducing travel time from 10 hours to three hours.

But in the first four days of operation, only 40 percent of seats were being sold, on average, according to media reports.