* State TV says lines to Jordan, Israel affected * Islamist groups called for pipeline attack - SITE * Security source say army closes main source of flow CAIRO, Feb 5 (Reuters) - Saboteurs blew up a pipeline that runs through Egypt's North Sinai and supplies gas to Israel, state television and other sources reported on Saturday. State TV quoted an official as saying that the "situation is very dangerous and explosions were continuing from one spot to another" along the pipeline. "It is a big terrorist operation", a state TV reporter said. A security source said the Egyptian army...