ISTANBUL - Turkish President Recep Tayyip Erdogan on Thursday called for a united front by Muslim leaders to fight extremism after the Paris attacks, warning that otherwise jihadists will commit further atrocities.

Erdogan warned that "calamities will happen again" if the rise of radical Islam is not halted in Europe, after the Paris attacks last Friday claimed by the Islamic State group which killed 129 people and suicide bombings in Ankara that left 103 dead in October 10.

"We are at a crossroads in the fight against terrorism after the Paris attacks," Erdogan told a meeting of the Atlantic Council think-tank in Istanbul. "I strongly condemn the terrorists, who believe in the same religion as me, and I am calling on all leaders of Muslim countries to put up a united front," he said.

"If not, those who knocked on our door in Ankara, will knock on your door elsewhere, as they did in Paris." Erdogan, a pious Muslim whose Justice and Development Party (AKP) spearheaded the rise of political Islam in Turkey, has long angrily dismissed suggestions that Ankara colluded with IS in the Syrian civil war.

Turkey has supported rebel groups throughout the over four years of conflict in Syria in the hope they can help oust President Bashar al-Assad from power. But Erdogan lashed out at any notion "that all Muslims are terrorists," saying: "Bad people can be Muslims as well as Christians and Jews." "Those who demonise Islam by looking at Daesh are making a big mistake," he said, using the Arabic acronym for IS. "Daesh has nothing to do with Islam."

With momentum building after the Paris attacks in the long-stalled bid of the world powers to find a solution for Syria, Erdogan made clear Turkey would not budge from its insistence that Assad must leave power. He accused Assad of supporting IS -- which is ostensibly fighting the Damascus regime -- and buying oil from the group.

"You would be blind not see it." "The chief reason for the humanitarian crisis and the rise of terrorism in the region today is Assad... Assad is waging state terrorism," said Erdogan. International efforts to find common ground on Syria have so far been thwarted by disputes with Russia, which has long insisted the Syrian people alone should decide the fate of Assad, a Kremlin ally. Turkey, however, has argued there can be no solution in Syria unless Assad leaves power.

Moreover, the Turkish authorities on Wednesday placed into administration a holding company close to the arch foe of President Recep Tayyip Erdogan, in the latest crackdown against his interests.

Acting on a court order, court-appointed trustees took over 19 companies, a foundation and a union connected with Kaynak Holding which is linked to the US-based preacher Fethullah Gulen, state media said.

The new administrators, escorted by anti-riot police, arrived at the headquarters of Kaynak Holding in the Uskudar district on the Asian side of Istanbul to take on their functions early Wednesday, the Dogan news agency added. The group is accused of financing the organisation of Gulen, which calls itself Hizmet (Service) but Turkey regards as a terror group aiming to overthrow the government.

Similar measures have already been taken against a Gulen-linked bank Asya Bank and media holding Koza Ipek which owns two pro-Gulen papers and TV channels. The authorities now refer to his group as the Fethullah Terror Organisation (FETO) but Gulen supporters ridicule the claims, saying their only crime is to oppose Erdogan.

A former close ally of Erdogan, Gulen went into exile in 1999 to escape charges levelled by the former authorities that were eventually dropped. He built up a vast array of interests in finance, the media and private education as well as enjoying influence in police and judiciary.

The current campaign against Gulen dates back to December 2013 when the government blamed him for sensational corruption allegations against Erdogan's inner circle and has since accused the ageing preacher, believed to be 74, of trying to overthrow the authorities.