On 29 October 1956, Israeli forces crossed the Sinai Peninsula, overwhelmed Egyptian army posts, and quickly advanced to their objectives. Two days later, British and French planes bombarded Egyptian airfields in the canal zone. Nasser ordered the military's high command to withdraw the Egyptian Army from Sinai to bolster the canal's defenses. Moreover, he feared that if the armored corps was dispatched to confront the Israeli invading force and the British and French subsequently landed in the canal city of Port Said, Egyptian armor in the Sinai would be cut off from the canal and destroyed by the combined tripartite forces. Amer strongly disagreed, insisting that Egyptian tanks meet the Israelis in battle. The two had a heated exchange on 3 November, and Amer conceded. Nasser also ordered blockage of the canal by sinking or otherwise disabling forty-nine ships at its entrance.