The Philippine National Police (PNP) said on Tuesday that Manila remains on “full alert,” following the arrest of a suspected ISIS leader in the capital city over the weekend.

Egyptian national Fehmi Lassoued was apprehended by joint Philippine police and military operatives, Rappler reports, and is suspected of working as a recruiter for the terrorist group after having worked as a commander for ISIS in Syria.

Authorities reportedly found illegal explosives and firearms in Lassoued’s apartment.

A spokesman for the PNP said Tuesday that law enforcement will remain on heightened alert for any possible terrorist attack following the arrest, adding that Lassoued may not be a “lone wolf.”

As focus shifts to ISIS activity in the country’s capital city, some have noted that the development could give the government ammunition for extending martial law across the country, not just in the southern island of Mindanao.

Earlier this month, a battalion of Philippine marines was reportedly sent to Metro Manila to help with the anti-terror campaign.