At least four Singaporeans are stranded in Xi'an, China, after their Tigerair flight was delayed on Wednesday (April 26) night, with police officers called in to contain the commotion by stranded passengers.

Mr Leong Siew Tim, an 80-year-old engineer, told The Straits Times over the phone that he and a friend were on flight TR2969, which was supposed to depart at 11.35pm on Wednesday.

"We were in the plane for almost two hours," he said. "Then they told us that the plane could not fly out and we will have to get out of the plane and then there were no clear instructions on what we were supposed to do."

Responding to ST queries, a Tigerair spokesman said the flight had been "retimed due to a fuel leak on the aircraft wing".

"The affected aircraft required more time for servicing and we hence applied for the necessary regulatory permits with the China authorities to send a ferry flight to Xi'an," said the spokesman. "In the meantime, our guests were accommodated in a hotel."

Mr Leong said the some 150 passengers on the plane waited until 3am in the morning. They were taken to a hotel and provided meals and were told that a bus would take them to the airport, where a replacement plane flying in from Singapore would take them home.

"When we were all in the bus, halfway to the airport, the bus turned back and we were told that the plane was not given approval to leave Singapore," said Mr Leong.

The group, which was made out mainly of tour groups from Malaysia, then returned to the hotel, he said.

"A big group gathered around and waited for 45 minutes for a Tigerair representative to come and explain to us the situation," he said. "The representative said the replacement plane will arrive from Singapore at 4am tomorrow (April 28)."

Mr Leong said that there was no representative accompanying the passengers at the hotel, to give instructions or updates.

"I think this is a very bad image of Singapore's airlines and I'm very disappointed," he said.

Mr Leong, who was there with a friend in his 50s, said there was another young Singaporean couple with them, but he is unsure how many Singaporeans are on the plane.

The airline paid for the hotel and the food, he said, but the group was very unhappy, and the commotion caused even resulted in police officers turning up at the hotel, he said.

According to airline tracking websites, the flight appears not to have departed, although it is unclear why.

Tigerair said in its response to ST that approval for the ferry flight was granted at 9.30pm on April 27 and the flight is expected to arrive in Xi'An at around 4am on April 28.

"The retimed flight TR2969 is now scheduled to depart for Singapore at 4.35am today," said the spokesman.