By Humeyra Pamuk and Dasha Afanasieva ISTANBUL (Reuters) - A Turkish newspaper said on Friday one of its journalists had been ordered to leave the country for criticizing Prime Minister Tayyip Erdogan on Twitter, raising concerns about media freedom a day after Turkey tightened internet controls. Today's Zaman said its online editor Mahir Zeynalov, 27, from Azerbaijan, was escorted onto a plane in Istanbul by police. The paper is close to influential U.S.-based preacher Fethullah Gulen, locked in a feud with Erdogan revolving around a corruption scandal shaking his government. Erdogan has cast the scandal as a bid by Gulen, who exerts extensive if covert influence in the police and judiciary, to unseat him and has responded by purging thousands of officers and more than 200 prosecutors.