Update 5 - details on police press conference. Last updated 6.15 p.m.

A 27-year-old Serbian man who was murdered in the early hours of this morning was stabbed once through the heart, the police said.

The stabbing took place in an apartment in Triq il-Merluz, Qawra during an argument about loud music.

The police said at a press conference this afternoon that the owner of the apartment cut off electricity as he had threatened to do if the young men persisted in playing loud music. The men - two from Macedonia, a Bulgarian and the victim, then argued among themselves and the victim was blamed for what had happened.

The Bulgarian is believed to have been the man with the knife. He is expected to be taken to court and accused of murder in the coming hours.

The weapon has been recovered.

All the men were in Malta legally

The crime was reported to the police at about 2.15 a.m. when a man who had apparently witnessed the stabbing called at Qawra police station and told police to go to the apartment.

The victim, Kristic Dragoljub, from Grocka, Serbia, died minutes after the police and a medical team arrived on the scene.

He arrived in Malta in October and worked in construction.

Blood could be seen on the steps and walls of three flights of steps in the common area of the apartment block. The victim was found on the landing between the first and second floors.

Neighbours said the stabbing took place in a top floor flat. The victim did not actually live there.

Very loud music - loud enough to annoy the neighbours - could be heard until shortly before the murder took place. Loud music was also heard from the apartment over the past few days.

This was the second murder in a week after the murder of a man who was shot five times outside his apartment in Marsa.

Video - Mark Zammit Cordina.