Police have ruled out robbery and would not be drawn on the motive for the killing.
"Police have fingerprinted and interviewed Pakistan's cricketers as part of the investigation"
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Mark Shields, the deputy police commissioner, said: "It could be one or more people that were involved in this murder."
"... Bob was a large man and it would have taken some significant force to subdue him and cause strangulation, but we do not know at this stage how many people were in the room."
He also said an individual or more than one person could have entered Woolmer's room before him as "the room was undisturbed and all his belongings were intact".
he said: "Hopefully we will bring the killers to justice as soon as possible.
"We will use every energy we possibly have to track down the killers."
Shields appealed for the killer or killers to give themselves up, and asked for witnesses to come forward.
Police have fingerprinted and interviewed Pakistan's cricketers as part of the murder investigation.
Police also said that the hotel's security was being looked into.
Paul Condon, a former London police commissioner, is to assist in the probe.
Less than 24 hours before the murder of Woolmer, a former England Test batsman and South Africa coach, the Pakistani team had been eliminated from the Cricket World Cup in a shocking defeat to debutants Ireland.
The International Cricket Council said the World Cup - which lasts for seven weeks and culminates in the final on April 28 - will continue despite the murder investigation.
Kamal Hyder, Al Jazeera's correspondent in Pakistan, said the Pakistan president had conferred one of the country's highest awards, the Sitar-e-Imtiaz, posthumously on Woolmer.
"He called Mrs Gill Woolmer and said his services will be remembered by millions of Pakistanis. There is gloomy sadness in Pakistan today," Hyder said.
"There has been a lot of talk from the people of Pakistan about a 'betting mafia' that wanted to silence Bob Woolmer.
"There has been talk that perhaps there had been foul play ... that he had some evidence against them which he was going to talk about in his autobiography which he was going to release very soon ... and that he may have been murdered by the 'betting mafia'."
Lloyd Beckford of Jamaica's CVM-TV, who spoke to Jamaican police, said: "At this point they are saying that they have not looked at security videotapes in order to look at possible suspects.
"But what they do know is that there was no forced entry.
"Sources have told us that the Pakistan team might not return to Pakistan until Tuesday and some more of them will be interrogated or interviewed."