Thunderstorms caused a power failure on the Beijing-Shanghai high-speed railway on Sunday, paralyzing southbound trains for 90 minutes, railway authorities said.

It was the first major malfunction since the line was launched on June 30.

The Beijing railway bureau said in an announcement that thunderstorms and gales in Shandong province caused a glitch to the power supply network between Qufu and Zaozhuang at 6:10 pm on Sunday.

The problem was fixed at 7:37 pm and operations resumed soon afterwards, it said.

Nineteen trains heading south on the 1,318-km rail line would arrive later than scheduled, the bureau said.

Shanghai railway bureau also said, through its official micro blog, that some 11 trains heading to Shanghai had been delayed for more than two hours because of the power failure.

The Shanghai station has arranged additional buses and taxies to carry passengers.

According to netizen's accounts on micro blogs, the first train to be hit by the power failure was G151, which left Beijing at 3:30 pm and was scheduled to arrive at Shanghai at 9 pm.

The train suddenly stopped on a bridge, during a storm, at around 6:10 pm, said netizen "Susan Chen" in her micro blog.

"The light is off, air conditioning is off, carriage is stifling, and there is a lack of oxygen," she said.

Netizen "Banalin", who took the train to his hometown Changzhou in Jiangsu province, wrote in his micro blog: "After waiting in the sweltering carriages for more than half an hour, passengers began to lose patience and became agitated."

Another passenger wrote that the public address system on the train kept explaining that the breakdown was due to the heavy rain.

After being stationary for more than two hours, with the carriage lights suffering intermittent disruption, G151 finally resumed running at 8:10 pm. Passengers were later given bread and water.

A passenger surnamed Wang on train G21, which set off from Beijing at 5 pm and was scheduled to reach Shanghai by 21:55 pm, said her train was stranded halfway for one hour in Jinan, Shandong.

"Some 1,000 passengers sat in the darkness. Air conditioners did not work during this time," she said.

The train then started running for about 20 minutes, then stopped again.

"I am a little bit scared, and some kids started crying," Wang said.

Wang said some passengers complained and attendants kept apologizing.

"Almost all the facilities in the train were out of service. We were very hungry and could not even grab a cup of water. It was terrible," she said.

The accident has increased safety concerns about the landmark railway, which opened one year ahead of schedule.

A publicity official with the Ministry of Railways explained that the delays were to ensure passenger safety.

There were similar incidents in 2007, the first year that China started to use bullet trains.

Still, many micro-bloggers said they would not choose high-speed trains after this incident, as punctuality and the ability to operate regardless of the weather were meant to be its advantages.