GEORGE TOWN • The Malaysian police have stepped up security at all public places in Penang as a precaution against the threat of attacks by the Islamic State in Iraq and Syria (ISIS).

State police chief Abdul Ghafar Rajab said the authorities were conducting constant surveillance at a number of places, the Bernama news agency reported. Penang is a popular tourist venue, including with Singaporeans.

He added that police were prepared to foil any attempt by ISIS to stage a terror attack. "We are ready to face any possibility and will not stop (our surveillance) until the threat is over," Bernama quoted him as saying yesterday.

Datuk Abdul Ghafar called on the public to inform the police of any suspicious activity that may pose a threat to national security.

With Malaysia Day coming up on Friday, federal Deputy Inspector- General of Police Noor Rashid Ibrahim had said earlier that police were stepping up the nationwide alert to thwart any attempt by ISIS militants to disrupt the celebrations.

He had said that police were not ruling out the terror threat following the arrests in Kuala Lumpur, Selangor and Pahang of three suspected ISIS militants who had intended to launch attacks on Aug 30, the eve of Malaysia's National Day.

Malaysia has been on high alert since last year, when police uncovered threats against the country's top leadership, including Prime Minister Najib Razak.

Kuala Lumpur had its first ISIS attack in June, when eight people were injured in a grenade attack on a bar in Puchong. The police arrested 15 Malaysians in a counter-terrorism swoop after the attack.

While the authorities have been conducting stringent patrols in the city as well as places frequented by tourists and expatriates, the unexpected bombing of a suburban bar filled with locals showed just how difficult it is to prevent attacks.