Prime Minister Najib Abdul Razak today vowed to bring to justice those responsible for stabbing to death two British medical students in Sarawak.

Najib expressed his condolences to the families and friends of the victims, Neil Dalton and Aidan Brunger, who were killed Wednesday in Kuching.

"Those responsible for their deaths must be brought to justice," Najib tweeted.

Dalton and Brunger, both 22, were on a six-week work placement with five other medical students, said Tony Stevenson, Newcastle University's acting vice chancellor, on the university's Facebook page.

Police arrested four Malaysian suspects and found a knife that was believed to have been used in the crime.

Investigators said there had been a quarrel between the students and the suspects.

The victims arrived in Kuching in June for training in a local hospital and were due to return to Britain later this month.

- dpa