The United Arab Republic to-day [June 6] declared the Suez Canal closed to all navigation because of alleged Israeli attacks against ships in the vital waterway. A communiqué issued by the United Arab Republic’s Supreme Command said: “Because of the intervention by the American and British Governments in Israeli military aggression and the air protection they provide for Israel from aircraft carriers it has become necessary to halt officially navigation in the Suez Canal.” The announcement over Cairo Radio said there was also the danger that a ship might be attacked in the canal and thus block the waterway. All ships presently in the canal were ordered to leave it immediately, the announcement said. The Radio did not identify the ships which it said had come under Israeli fire. The U.A.R. announced yesterday [June 5] that Isreali planes had fired on a French oil tanker in the canal apparently without hitting it. The Radio, said Isreali planes had dropped “strange objects” in the Suez Canal. The objects were not identified. Britain would strongly oppose Egypt’s decision to close the Suez Canal, authoritative sources said in London to-day [June 6]. The sources sold the measure was given top priority at a Cabinet meeting this morning [June 6] presided over by Prime Minister Mr. Harold Wilson. Whitehall sources dismissed as “absolutely unjustified” the Egyptian pretext for closing the canal – the claim that British and American aircraft had intervened in the conflict at Isreal’s side.