Services were disrupted along a new multi-billion-dollar Singapore metro line on Wednesday, the third straight day of rush-hour delays for the city-state's gleaming train system.
The problems lasted more than two hours and affected eight stations on the new 36-kilometre (22-mile) section of the metro, including stops that opened only six months ago.
The incident came two days after the start of public hearings over disruption in December that affected 127,000 commuters, some stranded for hours underground in the worst breakdown since the metro was inaugurated in 1987.
About 18,000 passengers were affected by Wednesday's disruption, operator SMRT Corporation said in a statement which blamed an electrical fault.
"We are sorry for the inconvenience caused to commuters and the public," the company's acting chief executive Tan Ek Kia said.
Since the breakdown in December, delays and problems have occurred with increasing regularity. In the past week alone there have been four disruptions in different sections.
The Circle Line, where the problems occurred, cost in excess of US$6.40 billion and took a decade to build, according to local media.
"The frequency of the breakdowns is really alarming," Shanta Arul, a 24-year-old communications officer, told AFP.
"The main concern here is that it is a brand-new line. The other breakdowns were on the other older lines but this is new, so it raises questions on maintenance and the quality of equipment and trains they are using."
The metro was once regarded as one of Asia's best but its image has suffered because of breakdowns blamed by Singaporeans on mismanagement and overcrowding due to a spike in the intake of foreign workers and immigrants in recent years.
The train system, which includes underground and overhead sections, registered an average 2.41 million passenger trips per day in 2011, according to local media. Official figures were not immediately available.