The EU anti-terrorism chief Gilles de Kerchove has revealed that in total more than 3,000 Europeans are believed to be in the ranks of the Islamic State at home and abroad.

Mr. Kerchove, who made this revelation during an interview with the BBC earlier in the week, also noted that the US-led airstrikes against the terrorists increases the likelihood of retaliatory attacks in western countries.

Since the beginning of the month, western nations have been on high alert following ISIS' orders for terrorist attacks abroad. Last Sunday, about 800 Australian security operatives participated in an early morning search of Muslim populated suburbs in Sydney and Brisbane. The raid, which has been described as the largest anti-terror raid in the history of the country, was reportedly instigated by intelligence findings that Australian ISIS militants were ordering their colleagues back home to stage 'demonstration killings.' Also, on Thursday, British police arrested 9 suspects during a raid on about 19 addresses in the capital of the country.

Experts say European militants in the ranks of ISIS exert a powerful sway over their companions back home and can influence them into committing atrocious deeds. According to Mr. Kerchove, who highlighted on the role of social media in the recruitment of foreign jihadists, the fact that the Islamic State has attempted to rebrand itself into a caliphate has endeared the group to many Muslims in Europe. He also warned that other terrorist groups - such as Al Qaeda - may be forced to stage a high profile attack to overshadow the growing popularity of ISIS.

Reports indicate that more than 40 countries have joined the US-led alliance, which has set out to stifle the expansion of the terrorists by launching air raids on their leaders, weapon stockpiles and other key facilities. The Russian government has also offered to assist Iraqi authorities in fighting this anti-democratic scourge.

ISIS shot into international attention after staging attacks in Syria and northern Iraq earlier in the year. The group, who currently control large parts of Syria and swatches on northern Iraq, is estimated to number about 30,000.