Shanghai: Shanghai officials say at least 271 people were hurt when a subway train crashed into another that was stopped underground.

The crash occurred yesterday afternoon after Shanghai Shentong Metro Group blogged that Line 10 was having delays due to equipment problems. The line opened last year and is one of the newest in the city.

The city's health bureau said 271 people were hurt, none seriously.

The subway operator said problems with signalling equipment appeared to have caused the accident.

The metro operator said none of the injured had life-threatening injuries, though some of the injured were carried away on stretchers.

"This is the darkest day ever for the Shanghai subway. Regardless of the cause or responsibility, we are stricken with remorse for having caused our passengers injury and losses," the company said in an apology posted on its blog. "We want to deeply, deeply apologise."

The crash follows a July 23 collision of two bullet trains in southeastern China that killed 40 people and injured 177, bringing into the open festering resentments over the huge costs of the country's massive build-up of its rail system, especially its high-speed trains.

Probe under wraps

Authorities have not yet disclosed the results of an investigation into the cause of that accident, though state media cited officials saying signalling equipment was thought to have been a key factor. In yesterday's crash, one train rammed into the back of another that was stopped between stations. Reports said problems with signaling equipment had prompted the line to switch to manual operations.

The trains were relatively crowded when they crashed in midafternoon. Photos posted online by passengers showed some of the injured covered in blood and lying on the floor of the train.

Firemen helped evacuate the approximately 500 passengers on the trains, taking them out through emergency exits and walking them through the subway tunnel.

The crash snarled downtown traffic as police blocked roads to clear the way for ambulances, and hundreds of gawkers gathered to watch as passengers were escorted from the subway.