At dawn on September 5th, 1972 a band of 'Black September' Arab guerrillas () broke into the Israeli(以色列)building in the Olympic village near Munich(慕尼黑)where 10,000 athletes were staying. Over 250 plain clothes police had been brought into the village, following a tip-off trouble ahead, but none of them saw the Arabs scale the fence. They burst into the Israeli building with submachine guns blazing at 5:10 am. Some Israeli athletes escaped through the windows and side doors. Nine were taken hostage. The guerrillas demanded the release of 200 Palestinians(巴勒斯坦) held in Israeli jails and a safe passage out of Germany. Within hours the Olympic village was surrounded by 13,000 police. The Olympic s were suspended. After some negotiations, the terrorists were told they would be flown with their hostages to an Arab country. They were taken by helicopter to the Fursten field military airport 25 miles from Munich. Just before midnight the guerrillas and their hostages began to walk across the tarmac(停机坪)to a waiting Boeing 727 aircraft. Suddenly all the airport lights were turned out and German police sharp shooters opened fire. The rescue attempt failed tragically. In the gun battle all nine hostages were killed, as well as four Arabs and one policeman. Three Arabs were captured and one escaped into the nearby woods. On the 8th, Israeli planes bombed ten guerilla bases in revenge for Munich massacre. Israeli athletes were attacked and kidnapped possibly because ______.