Turkish Airlines allegedly shipped weapons to unknown groups in Nigeria, which has been ravaged by violence between the army and Boko Haram militants, a[n]...incriminating phone call [has] revealed...In a tape posted on YouTube, Mehmet Karatas, an assistant executive of the airline, allegedly tells Mustafa Varank, an advisor to [Turkish Prime Minister Recep Tayyip Erdogan]...that he feels guilty over [the] national flag carrier's arms shipment to Nigeria. "I do not know whether these (weapons) will kill Muslims or Christians. I feel sinful," Karatas is allegedly heard saying. The leaked call has the potential to harm the airline's image...which is 49 percent state-owned...The Turkish [prime minister]...has dismissed...the tapes as "vile" fakes...