Malaysia’s national police chief Khalid Abu Bakar said in a statement on Sunday that the suspects were detained in separate security raids in a western suburb of the capital.
He added that the detainees, who are suspected sympathizers of Takfiri ISIL terrorists, were planning to target "strategic" spots in and around the capital city.
"They had planned to launch attacks in Malaysia on April 25 and April 26," the statement read.
Meanwhile, law enforcement agencies and security forces said they have seized a large quantity of weapons and remote-control devices from the militants’ hideout.
The developments come as Malaysia is set to host a regional summit of the 10-member Association of Southeast Asian Nations (ASEAN). The summit is set to kick off on Monday in Kuala Lumpur before shifting to the resort island of Langkawi.
Malaysian authorities plan to call at the gathering for regional anti-terror coordination.
Malaysian authorities have detained scores of people believed to be supporters of the Takfiri ISIL terrorist group.
Last month, the Malaysian Home Ministry presented a proposal including two new anti-terror laws to curb militant acts in the country.
Malaysian authorities are worried that the ISIL terrorist group is gaining an increasing number of recruits and supporters in the country.
The government has identified nearly 70 of its nationals who have joined ISIL in Syria and Iraq, and five who have been killed while participating in the group’s terrorist activities.
Malaysian security sources say another 120 people, including men and women, with suspected links to the ISIL are being kept in custody.
The Takfiri group, which controls some parts of Iraq and Syria, has launched a huge publicity campaign to recruit people from all across the world. The group has been committing heinous crimes including the beheading of civilians and non-civilians in the areas under their control.