TWO city Metro lines suffered separate breakdowns during morning rush hour yesterday, causing delays for thousands of commuters.

Officials of the Metro operator said they steered would-be riders away from the affected stations, urging many to take buses or taxis, but the delay proved short-lived.

The morning got off to a troubled start at 7:48am, when a train on Line 3 stopped for about 10 minutes because of a malfunctioning carriage door.

Around 9am, Line 2 suffered a signal failure from a power glitch, causing a 12-minute delay between People's Square Station and Zhongshan Park Station - the city's two busiest Metro hubs.

The line soon went back to service, with officials saying the signal was just "unstable."

"I was really worried that I would be stuck in the train for a long time," said a passenger surnamed Meng who took Line 2 yesterday morning.

Breakdowns have been unnerving to passengers ever since July 14, when Line 2 suffered a delay of more than 50 minutes during the morning rush.

The July delay, caused by a power surge and a train breakdown, inconvenienced hundreds of thousands of passengers and stirred up much anger.

On September 9, a signal glitch caused a 30-minute delay at Zhangjiang High-Tech Station on Line 2.

Passenger grumbles seemed to decrease after a new public information system, designed to give a heads-up on breakdowns so commuters can take alternative transportation, went into effect in August.