Malaysian police say a grenade blast at a bar last week that injured eight people was the first attack in the country by the Islamic State militant group, and that 15 people have been detained.

Police initially said the June 28 explosion outside Kuala Lumpur was related to a business rivalry, or a revenge or target killing.

National police chief Khalid Abu Bakar said Monday that a subsequent investigation showed that the blast was carried out by the Islamic State group.

Khalid said 15 people, including two factory workers who allegedly committed the crime, have been detained.

More than 150 militant suspects have been detained in Malaysia over the past two years.