Controversy is growing in Switzerland over an alleged secret deal, made almost 50 years ago, between the Swiss government and the Palestine Liberation Organisation (PLO).
The agreement, detailed in a new book, was apparently designed to prevent terrorist attacks on Swiss territory.
In return, Switzerland would offer diplomatic support to the PLO.
It followed a series of attacks in 1969 and 1970 by Palestinian groups that caused huge concern in Switzerland.
In February 1969 gunmen opened fire at Zurich airport on an El Al plane, whose pilot died in the attack. The Swiss arrested the attackers
In 1970, a bomb on board a Swissair flight to Tel Aviv brought the plane down just outside Zurich, killing all 47 passengers and crew
In September 1970, a Swissair flight on its way to New York was hijacked. Two other airliners, one British, one American, were hijacked at the same time. All three ended up at Dawson’s Field airstrip in Jordan, where more than 300 passengers were held hostage