Police have detained several more suspects believed to be linked to a grenade attack at an entertainment premises in Puchong.

Inspector-general of police Khalid Abu Bakar in confirming the latest arrests said they (suspects) were in addition to 15 individuals who were detained on June 28 and July 1.

"All of them are believed to be involved in Islamic State activities. However, two more main suspects are still at large and police are still tracking them down," he said without revealing the number of suspects picked up.

Khalid was met by reporters after attending a Bukit Aman Special Branch Aidilfitri open house celebration at the senior officers' mess in Kuala Lumpur today.

Also present was Deputy Home Minister Nur Jazlan Mohamed.

In the explosion at an entertainment outlet at the IOI Boulevard, Puchong on June 28, eight people were injured, one seriously.

Police are now on a manhunt for two locals identified as Md Saifuddin Muji, 28, and Jasanizam Rosni, 33, both from Johor, as they are believed to have received orders from Malaysian Islamic State terrorists in Syria to carry out the attack.

Meanwhile, Khalid said the security at the main entrances of the KLIA and KLIA2 will continue to be tightened as a precaution against threats by the IS militant group.

He said the police recently held meetings with the Transport Ministry to discuss a number of proposals regarding security.

"We have put forward some suggestions and input (on security) to the ministry to increase the level of security of passengers and tourists who are at the airports.

"There is no need for me to comment further on the matter here, let the transport minister (Liow Tiong Lai) announce it later," he said.

On Friday, Deputy Prime Minister Ahmad Zahid Hamidi said the government was considering a proposal to allow only passengers into terminals at all major airports in Malaysia, to increase safety.

According to him, the cabinet at a meeting on Wednesday proposed that only passengers should be allowed to be at the check-in counters while family members accompanying them should be either outside the building, or at a designated place.

The Transport Ministry had also been directed by cabinet to find a mechanism to ensure vehicles dropping off or waiting for passengers are not situated near the terminal buildings.

In another development, when asked on the motive of a shooting incident in which a real estate agent was killed in Jalan Hujan Emas 4, Taman OUG on July 1, Khalid said the incident was still under investigations.

"I will not reveal the motive of the incident, let the motive of the case be disclosed in court," he said.

- Bernama