KUALA LUMPUR: The Movida nightclub was targeted by Islamic State (IS) because it was considered an “unIslamic” establishment, said Tan Sri Khalid Abu Bakar.

The Inspector-General of Police said the bombing, the first ever by IS on Malaysian soil, was only step one of a series of attacks planned by the group.

"The two men who carried out the attack were also targeting senior leadership of the country, top police officers and senior members of the judiciary because they felt that these three groups were the main obstacles to their activities.

"They were receiving instructions directly from IS militant Muhamad Wanndy Mohamad Jedi from Syria," he said at a press conference here at Bukit Aman on Monday.

Police have since arrested the two bombers and 13 other IS-linked Malaysians in a series of arrests between the day of the attack on June 28 and July 1.

"Among those arrested, two of them are low-level police officers in Kedah and Penang.

"One of them had planned to carry out robberies to help fund an IS cell while the other was protecting a senior IS member from detection," Khalid said.

He said of the 15, aged between 19 and 52, seven were nabbed in Kedah, four in Selangor, two in Kuala Lumpur, one in Penang and one in Malacca.

"The two who threw the grenade were picked up on July 1 at a factory in Port Klang where they worked.

"We believe they got the grenade, an old model used in World War II, from a neighbouring country," he said.

Khalid said police were also on the lookout for two more men who were behind the bombing.

He urged anyone with information about the duo, identified as Md Saifuddin Muji, 28, and Jasanizam Rosni, 33, to contact the police immediately.

The bombing that injured eight people was a very disturbing development, said Khalid.

"Prime Minister Datuk Seri Najib Tun Razak contacted me and has given me very strict instructions about this," he said.

Khalid said all those arrested had been recruited and given instructions through social media, which would be scrutinised in even more detail from now on.

He also urged nightclubs and similar outlets to take extra precautionary measures.

"Try to make sure people are not able to enter the place so easily and adhere to the opening hours instructed by the local councils," he said.