A Russian-built, Kilo-class diesel submarine recently purchased by Iran, is towed by a support vessel in this photograph taken in the central Mediterranean Sea during the week of December 23. The submarine and the support ship arrived at Port Said, Egypt, on Tuesday and were expected to begin transiting the Suez Canal today, Jan. 2, 1996. Ships and aircraft from the U.S. Navy's Sixth Fleet are tracking the submarine, which has been making the transit on the surface. This is the third Kilo-class submarine the Iranians have purchased from Moscow.