SEMPORNA (THE STAR/ASIA NEWS NETWORK) - The Sabah Eastern Security Command (Esscom) is not discounting the possibility that the shootout on Mabul island was in retaliation to security forces having intensified enforcement in the state's eastern waters, said Esscom commander DCP Datuk Abdul Rashid Harun on Sunday.

Abdul Rashid said that the eight gunmen in Saturday's attack could have planned to carry out a kidnapping at one of the island's resorts but instead, attacked the two policemen.

"If this is the cause, this means that the security forces sacrificed to prevent a kidnapping from taking place," he added.

On Saturday, Kpl Rajah Jamuan went down firing at heavily armed Filipino gunmen as they were believed to have grabbed his colleague in the 11pm raid.

The 32-year-old from Semporna and marine police constable Zakiah Aliep, 26, were attacked as they were having a meal at the security post at the Mabul Water Bungalows Resort.

Rajah's body was found below the jetty of the resort while Zakiah was reported missing.

Three other marine personnel in a patrol boat close to the area moved in to assist as the gunmen fled.

The marine team immediately alerted their base as security forces within Esscom immediately put in place Ops Tutup.

A massive sea and air hunt was launched early Sunday.

The masked gunmen clad in military fatigues have reportedly crossed over to the Tawi Tawi chain of islands in southern Philippines.

The raid is widely seen as a "revenge" attack against security forces because of recent clampdowns against militant and kidnap-for-ransom groups operating in Sabah's east coast.

Earlier, sources said that initial indication was that the gunmen might have rowed slowly into the area with their boat during low tide before climbing up the resort's jetty from the back of the building.

Shooting started as soon as they entered the building.

The gunmen are believed to have grabbed marine police constable Zakiah while shooting their way out and fleeing towards their waiting boat to make their escape.

One of the policeman Sjn Jeffridin, who was on a boat with two others nearby, heard the commotion and went to investigate. He found two of his colleagues had gone missing, it is learnt.

Most resorts guests and workers were already in their rooms and sleeping when the incident occurred at the resort whose villas sit on stilts while people at resorts along Mabul Island beach only said that they heard gunshots but remained indoors until morning.

"We heard the shooting but we did not come out. At 6.30am (Sunday), I went to ask the General Operations Force (GOF) personnel (stationed on Mabul) if anything had happened, they told me nothing happened.

"But I read on online news that there was shooting and kidnapping,'' a resort worker said on condition of anonymity.