Despite fewer violent incidents, tensions remained high at the "blue line" serving as a border between Israel and Lebanon, U.N. Secretary General Kofi Annan said Thursday. He said in a six-month report to the U.N. Security Council that "hostile rhetoric" has remained the norm while "rogue acts" had flared up in January with violations of the air space over the blue line. The line was set up by the United Nations in 2000 to mark the final withdrawal of Israeli forces from southern Lebanon. Annan asked the 15-nation council to extend the mandate of the U.N. peacekeeping force in southern Lebanon, known as UNIFIL, for another six months, ending on July 31. "UNIFIL will continue to contribute to the restoration of international peace and security by observing, monitoring and reporting on developments in its areas of operation and liaising with the parties to maintain calm," he said. --More 2332 Local Time 2032 GMT