Bukit Aman's Counter Terrorism Special Branch has arrested nine suspects, including a 17-year-old teenager, for suspected involvement in Daesh militant activities, from July 20 to August 9 this year.

In the operation around Kuala Lumpur, Johor, Sabah and Kelantan, three foreigners and six Malaysians aged between 17 and 56 years old were arrested.

"The three foreigners are former soldiers, three others are video compact disc (VCD) sellers, while the rests are a factory operator, a bulldozer driver and an unemployed," said Inspector General of Police (IGP) Tan Sri Khalid Abu Bakar.

They include Md Saifuddin Muji, 28, and Jasanizam Rosni, 33, suspected to be involved in the hand grenade explosion at an entertainment centre in Puchong on June 28.

They were arrested on August 9, Khalid said in a statement today.

"They fled after the attack incident and hid in a hut in a hilly area in Kuala Krai, Kelantan since early July 2016," the top police said of the duo.

"These two men had been waiting for Muhammad Wanndy Mohamed Jedi's orders to launch an attack on an entertainment centre in Johor Bahru," he said referring to a Malaysian Daish member in Syria.

"Police seized an M67 hand grenade meant for the attack," he added.

Following the arrests, police seized an M67 type hand grenade hidden in Rengit, suspected to have been used in the planned attack.

The two suspects arrested in Batu Pahat, Johor and Kuala Krai, had conspired to harbour Jasanizam and Md Saifuddin.

Khalid said some of the suspects had been planning to carry out a number of attacks in the country.

According to him, the teen who was detained in Sabah had planned to carry out a lone wolf attack to slaughter non Muslims in Sandakan.

The teenager had also issued threats in his Facebook account about killing the IGP.

"Another suspect, aged 26, who was detained in Johor had planned to carry out attacks on Bukit Aman and the government administrative complex in Putrajaya," he said, adding he was also believed to be receiving orders from Muhammad Wanndy.

Khalid said the three foreigners were detained on suspicion of using Malaysia as a transit to obtain fake travel documents.

"They also planned to launch attacks in a country in the Middle East," he said without naming the country.