GETTY The Islamist would-be bomber was planning on targeting Germany's intelligence agency

FREE now and never miss the top politics stories again. SUBSCRIBE Invalid email Sign up fornow and never miss the top politics stories again. We will use your email address only for sending you newsletters. Please see our Privacy Notice for details of your data protection rights.

A 51-year-old employee of the domestic intelligence service has been arrested after he made Islamist terror inspired comments on social media. The German national is understood to have been planning to detonate a bomb in the Bundesamt fur Verfassungsschutz (BfV) building and offered to share classified information with terrorists.

A spokesman for the intelligence agency said: "There is no evidence to date that there is a concrete danger to the security of the BfV or its employees. "The man is accused of making Islamist statements on the Internet using a false name and of revealing internal agency material in Internet chatrooms." The spokesman said the suspect had not previously attracted attention, adding: "The man behaved inconspicuously during his employment process, training and in his area of responsibility."

Countries most affected by terrorism in 2016 Fri, November 25, 2016 Terrorist attacks have been prevalent in the news this year. In fact, there's been an incident every single month. Here we list the countries most affected by terrorism in 2016. Play slideshow Getty 1 of 12 Countries most affected by terrorist attacks in 2016

The arrested man converted to Islam two years ago and had made a pledge of allegiance to the Austrian ISIS fighter Mohamed Mahmoud, Der Spiegel reported. Mahmoud was initially jailed for supporting al-Qaeda and he started a banned extremist organisation before being expelled from Germany. He appeared in an Isis propaganda video calling for a wave of devastating terror attacks across Europe last year. Speaking in German, he ordered viewers to “pick up a big knife, go down to the streets and slaughter every infidel you encounter” before shooting a prisoner in the head. German authorities have ramped up their surveillance of potential militant Islamist groups and individuals after two attacks claimed by the Islamic State group in July. The BfV estimates there are about 40,000 Islamists in Germany, including 9,200 ultra-conservative Islamists known as Salafists, Hans-Georg Maassen, who leads the agency, told Reuters in an interview earlier this month.

GETTY The intelligence hub is in Cologne and authorities say they never suspected the man