SINGAPORE (Reuters) - Singapore said on Tuesday it had detained an auxiliary police officer for attempting to undertake armed Islamist violence overseas, and it also banned nine publications by a preacher for containing extremist religious views.

The city-state has increased its level of surveillance for Islamist radicalism as concern grows about the spread of Islamic State in the region.

Singapore has been urging citizens to report anyone deemed at risk of being radicalized, and has reiterated over the past year that it is a target of Islamist groups.

The Ministry of Home Affairs said auxiliary policeman Muhammad Khairul bin Mohamed, 24, had been arrested in May and officially issued with a detention order this month under the Internal Security Act (ISA), which allows for suspects to be held for lengthy periods without trial.

Khairul, whose path to radicalism began in 2012, intended to undertake armed violence in Syria and was interested in joining the Free Syrian Army or other militant groups operating there, the ministry said in a statement.

“His readiness and proclivity to resort to violence in pursuit of a religious cause makes him a security threat to Singapore,” it said.

A colleague, Mohamad Rizal bin Wahid, was put under a restriction order for supporting Khairul’s intentions to engage in armed violence in Syria, it said.

Auxiliary police are private contractors hired to perform certain security duties. Both men were in the auxiliary force at the time of their arrests last month.

Rizal did not share Khairul’s desire to participate in armed violence but he had failed to bring the matter to the attention of authorities and had even suggested to Khairul various ways to get to Syria and die there as a “martyr”, the ministry said.

The news comes just a week after authorities said that they had detained the first Singaporean woman for suspected Islamist radicalism.

At least 16 Singaporeans have been put under restriction or detention orders under the ISA since 2015 because of their radicalization, up sharply from 11 cases between 2007 and 2014, according to ministry data.

In a separate statement, the Ministry for Communications and Information said it banned nine publications by another Singaporean, Rasul Bin Dahri, that contained extremist religious views.

It said in some of his publications, the preacher rejected the idea of a secular state and called on Muslims to establish an Islamic State.

“Rasul Bin Dahri is a Singaporean who has, through his radical teachings, betrayed the values that Singapore has held so close to us as a multi-cultural and multi-racial society,” the ministry said in a statement.

“We will not allow his radical teachings and his extremist ideology to take root in Singapore,” it said, adding distributing or possessing any of the prohibited publications would be an offence.

It was not immediately clear whether the preacher will face any other action. Reuters was not able to contact him for comment.