German intelligence is carefully watching 90 mosques for signs of terrorist activity as the head of the service warns Salafism is on the rise.

The German Federal Office for the Protection of the Constitution (BfV) has expressed growing anxiety over mosques that may be linked to terrorism. “We are concerned that there are many mosques in Germany that we must look at,” said Hans-Georg Maassen who heads the domestic security agency.

He told German TV that they were looking not only at established mosques but also what he called “back-yard” mosques that are out of public view. These under the radar mosques are usually headed by self appointed imams who Maassen says frequently incite their followers to jihad, Frankfurter Allgemeine reports.

Maasen said that Germany needs to be serious in tackling the problems of Islamic fundamentalism and that would require the help of the Muslim community as much as government legislation. He described a “coalition against extremism” which would include Muslims, though he said that the current debate on the public role of Islam in Germany is “a topic of political discourse” and not the under the jurisdiction of his agency.

The words come in sharp contrast to some who say that the call for banning public symbols like the minaret, proposed by the anti-mass migration Alternative for Germany (AfD), are unconstitutional. Maassen said of the right wing party, “when the AfD are extremists, we look at them – just as we do with other parties,” but stressed he didn’t currently regard them as extremist.

The security chief also talked about the ever present threat of a terror attack on German soil from the Islamic state. “The risk situation, we see as very serious. It has increased in recent months in Western Europe,” he said and noted that the agency was on high alert for a potential act of terror saying that Germany is at as much risk as France or Belgium.

The threat from the Islamic state is complex he warned at a press conference Monday saying, “we must continue to take into account multiple attack scenarios, by a plurality of cells to various destinations and possibly over several days.” His statement comes after reports that the Islamic State network in Europe is much bigger than European police had previously thought earlier this year.

The agency said that the number of Muslims who believe in radical Islam has also grown substantially in number. Maassen said that there were at least 8,650 Salafists in Germany which is double the number from four years ago. Maassen and the agency believe the rise in number has much to do with internet radicalization and the slick propaganda of ISIS which was blamed for the radicalization of the two teens who carried out a terror attack on a Sikh temple last month.

A new ruling by the German constitutional court that said the Islamic state is not sufficiently dangerous to respond to earned the ire of Maassen who said that ISIS is engaging in asymmetrical warfare and that for Germany it is “a direct national interest that the Islamic State is eliminated.”