ISTANBUL - Turkey is preparing a formal extradition request for US-based cleric Fethullah Gulen on suspicion that he organized an attempted coup involving several thousand soldiers, President Tayyip Erdogan's spokesman said on Tuesday."If the US insists on keeping him, people will start thinking they are protecting him," Ibrahim Kalin told reporters in Istanbul."A person can easily be extradited on the basis of suspicion, and on this occasion there is a lot of suspicion that he orchestrated this," he said.Kalin said the coup attempt was carried out by a tiny fraction of the army and would not affect Turkey's fight against Islamic State or Kurdish militants. He described the armed forces as the "final stronghold" of Gulen's network.He said 14 soldiers had been detained in the coastal town of Marmaris for an attempted attack on Erdogan during the coup bid, but that several members of the group were still at large. No military vehicles, including tanks and helicopters, were unaccounted for, Kalin said.