Turkish police raided the Ankara offices of a media group critical of President Recep Tayyip Erdogan, one day after two British reporters were jailed on terror charges which activists say are spurious.

Koza Ipek Media’s offices were raided Tuesday and six people have been arrested so far. An arrest warrant has been issued for the conglomerate’s CEO, Akin Ipek, who is reportedly not in the country.

The move comes a day after a court in the country’s southeast linked two British journalists working for U.S.-based VICE News to the Islamic State group and ordered them remanded in custody on terror charges.

Ipek’s media arm owns the Turkish dailies Bugun and Millet, television stations Bugun TV and Kanalturk and the website BGNNews.com. Erdogan accused them of being closely linked to Islamic cleric Fethullah Gulen, Erdogan’s main rival who is based out of the U.S.

Erdogan has accused Gulen and his supporters of seeking to create a “parallel structure” of supporters in the judiciary, police and media in order to overthrow him.

Police searched all 23 companies owned by Koza Ipek, which include interests ranging from minerals to newspapers, on suspicion that the conglomerate was providing financial support to the “Gulenist Terrorist Group,” according to local media cited by Reuters.

Koza Ipek Chairman Akin Ipek condemned the raids and denied any wrongdoing. "If they find a single illegal penny I will give them the company as a present," he said, adding that he had previously submitted all documents that police had asked for, Reuters reported. "It is a total fantasy, an empty slander."

The move comes at a time when Turkey has stepped up its crackdown against journalists and media companies, drawing condemnation from watchdogs and international groups.

Kemal Kilicdaroglu, leader of the Republican People’s Party, the country's main opposition, accused police of suppressing dissent. "We cannot speak of democracy in a country where the media is being silenced," he said, according to Al Jazeera.

Turkey's new European Union Minister Ali Haydar Konca, a member of the pro-Kurd Peoples' Democratic Party, warned that any raids targeting the media reflected poorly on the country.

"I am worried that operations targeting the media will create great concern across the world about whether Turkey is a democratic country," he said, according to Reuters..