The attack by a mob on Sri Lanka's High Commissioner to Malaysia Ibrahim Sahib Ansar at the KL International Airport on Sunday is believed to be motivated by political reasons and anger.

Selangor police chief Abdul Samah Mat said police believed this was the case because prior to the assault incident, they had received 47 police reports objecting to the presence of former Sri Lankan president Mahinda Rajapaksa in the country to attend the International Conference of Asian Political Parties (ICAPP).

"So far five individuals suspected to be involved in the assault have been placed under remand, from yesterday till tomorrow.

"They were detained by a special task force at their respective homes, three in Sungai Siput, Perak, and one each in Rawang and Dengkil, Selangor. All are locals and it is understood they were angry about the presence of Rajapaksa in the country," he said.

He told this to reporters after attending Selangor police's monthly gathering at the Petaling Jaya police headquarters today.

He said the five were being investigated under the Security Offences (Special Measures) Act 2012 (Sosma).

"We also identified four of their accomplices, all locals, and are tracking them down.

On security aspects at KLIA, Abdul Samah said police were not informed about the presence of Ibrahim at the airport.

"Policemen could not take any action because they thought it was an ordinary fight and also did not know the person being attacked was the Sri Lankan high commisioner," he said.

Following the assault, the Sri Lankan Foreign Ministry in a statement on its website said the high commissioner was assaulted by a group of people at KLIA.

The incident happened at 3pm after Ibrahim had sent off Sri Lankan Minister of Primary Industries, Daya Gamage.

Ibrahim suffered bruises in the face and body and was sent to the Gleneagles Hospital in Kuala Lumpur for treatment.

It is believed those detained are sympathisers of the Liberation Tigers of Tamil Eelam, a terrorist group in Sri Lanka that was wiped out when Rajapaksa was president.

- Bernama