ISIS terrorist (file)
ISIS terrorist (file)Reuters

A day after Bulgarian security forces raided over 40 homes and a mosque in the southern part of the country, prosecutors on Wednesday charged an imam and six others detained in the operation with supporting the Islamic State (ISIS) terrorist group.

According to Reuters, charges against Muslim prayer leader Ahmed Mussa, five men and one woman include propagating an anti-democratic ideology and incitement to war, both verbally and with videos and images.

Islamic State, who control territory in Iraq and Syria, have carried out brutal killings of civilians, including highly publicized beheadings of foreign journalists and aid workers.

Western governments fear their own citizens who have joined the group to fight could return and carry out attacks at home.

Bulgarian security forces raided more than 40 homes and a mosque in southern Bulgaria on Tuesday to seize books and computers in a special operation aimed at uncovering radical Islamist activities.

Some 26 people were held for 24 hours and 30 witnesses were questioned during the operation, conducted by more than 400 police officers, security agents, prosecutors and investigators.

"(Mussa) is an intelligent man, so he has accepted the prosecutors' decision and he has not expressed indignation regarding his detention," Elvira Pankova, Mussa's lawyer, was quoted as having told reporters.

Investigators discovered a large number of shirts, hats, flags and banners with the logo of the Islamic State, Reuters noted.

Bulgaria’s Deputy Chief Prosecutor Borislav Sarafov said that Mussa, a former Christian of Roma origin who converted to Islam in 2000 while working in Vienna, had preached surrounded by the Islamic State flags.

The imam had told his followers to be prepared to fight against Christianity to achieve the ultimate goal of establishing a global caliphate, according to Sarafov.

He also said Mussa's group had attempted to recruit fighters for Islamic State and that the crimes in question were committed between July 2014 and November 2014.

So far, more than 15,000 foreign nationals are known to have entered Syria and Iraq to join the ranks of the Islamic State (ISIS).

Over 1,000 French citizens have reportedly left to join ISIS and there are also recruits coming from, among others, Russia, the United Kingdom and Ireland.