PETALING JAYA: Was it an impromptu or an unauthorised raid? This is the question Inspector-General of Police Tan Sri Musa Hassan wants answered after two policemen were shot dead and two others were critically wounded in a drug bust on Thursday.

"The two are still unconscious and we will only know what happened once we interview them after they regain consciousness.

"There are other angles we are also looking at. Right now we do not want to speculate," he said, adding that an internal investigation was being carried out by a special team.

Musa reiterated that the priority now was to hunt down the cop killers.

He urged those with information to come forward and help the police.

"We have lifted several fingerprints and sent them to the National Registration Department.

"I can only say that we are working on several good leads but I cannot tell you what they are as our operations will be jeopardised,'' he told reporters at his Hari Raya open house at the senior officers mess in Bukit Aman yesterday.

The IGP said he has sent a memo to all CID chiefs to ensure that all raids conducted by their men followed standard operating procedures and must be authorised.

"The raids or operations must be sanctioned and approved and anyone who goes against orders will be dealt with accordingly,'' he added.

Musa also criticised a couple of newspapers for interviewing witnesses and splashing their photographs in their publications.

Describing their reporting as 'irresponsible,' he said their actions had put the life of the witnesses in jeopardy and now the witnesses had to be given protection.

"Do not do such things just to sell your paper. Think of the lives of these people," he said.

The IGP also expressed his condolences to the families of the policemen who were killed.