SINGAPORE - A 42-year-old man was seen being stabbed repeatedly outside a Jalan Besar pub on Monday night after an argument with another man, in a case which police have classified as murder.

Police said they received a call for assistance at 11.19pm, and the victim was pronounced dead at the scene around 10 minutes later.

A 55-year-old man who wanted to be known only as Ah Huat, said he had been eating at a stall nearby and later saw the victim get stabbed thrice - in the chest, arm and leg.

The victim had been arguing with another man in a back alley when the man ran to a pub across the road. He then saw the victim try to get into the pub, called KSP Pub & KTV, but the man refused to let him. He later came out, and allegedly stabbed the victim.

Witnesses saw the suspect go back into the pub and flee through the back door. The victim was found outside a hostel called The Trey next door.

The hostel's manager, Mr Shammy, said he ran down to its entrance to try and save the victim, who was mostly bleeding from the chest.

"Blood was squirting out," said the 36-year-old, who tried to put pressure on the wound.

"That's all I could do. I felt helpless," he said, adding that he tried to get help but there was no one around.

When The Straits Times reached the scene at around 2am last night, police had yet to find a weapon.

"They had a huge argument," said Mr Low Chen Khang, 19, who works at a food stall across the road. "I saw one person stab another." He was on the second floor when he witnessed the incident.

A 65-year-old retiree who wanted to be known only as Mr Lim said: "I heard a commotion and walked over. I saw a man lying on the floor, covered in blood."

Someone was helping the victim and asked him what his name was, he said, but the victim could not speak.

Anyone with information is requested to call the Police Hotline at 1800-255-0000 or submit information online at www.police.gov.sg/iwitness. All information will be kept strictly confidential.