SINGAPORE - Passengers of a SilkAir flight, including Singaporeans, were stranded at Penang International Airport for about nine hours, as heavy rains and strong wind grounded flights in the Malaysian state.

MI351 was scheduled to depart at around 6pm on Saturday (Nov 4) but was repeatedly delayed and eventually cancelled at around midnight, said one of its passengers, Mr Felix Chen, 30.

A replacement flight MI9351, eventually took off at about 3am on Sunday, arriving at Changi Airport's Terminal 2 at about 4.30am.

Mr Chen, an advertising account manager who was in Penang for work, told The Straits Times: "I'm relieved that I'm finally home."

He said passengers were stranded at the airport because the roads were flooded.

The overnight storm started around 2pm on Saturday, according to reports, lasting over 18 hours until Sunday morning, with floodwaters rising up to 4m. At least four people have died. Military and police forces have been deployed to assist victims.

Mr Chen, who was on his way to the airport when it started to rain, said that floodwaters on the roads were above ankle height and visibility was very poor because of the deluge.

"The jam was quite bad. The driver had to drive very cautiously, and we took about 1 hour and 10 minutes to reach the airport," Mr Chen said.

While stranded at the airport, Mr Chen said passengers were given regular updates on the situation by SilkAir ground staff, who also provided them with burgers, sandwiches, water and coffee.

Upon his return to Singapore, he took to Facebook to commend the staff: "I would like to dedicate this post to the ground staff of SilkAir in Penang for the constant updates about the situation, and the assurance that we are in safe hands.

"You guys handled it professionally and I'm sure it's the best that you could have done during the time of uncertainty," he wrote.