Palestinian and Hizbollah terror cells are operating in the Egyptian Sinai desert and are in the advanced stages of planning an attack against Israeli holidaymakers, the Israeli Counter-Terrorism Bureau revealed this week.

The warning was part of a travel advisory in which the bureau urged Israelis not to visit the Sinai and to return immediately to Israel if already there. The Sinai Desert is a popular Israeli holiday site mainly due to its beautiful beaches and low costs.

Israel traditionally issues travel warnings ahead of major holidays such as Rosh Hashanah, but defence officials said that the current threat was real and backed up by concrete intelligence. The fear is that terrorists will try to kidnap Israelis and smuggle them into the Gaza Strip.

The IDF ordered all soldiers and career officers as well as civilians employed by the military not to travel to the Sinai.

Last month, the bureau issued a general advisory urging Israelis worldwide to take precautions since Israelis were at risk of being kidnapped by Hizbollah, still seeking to avenge the February assassination of Imad Mughniyeh, one of the group's commanders.

Defence Minister Ehud Barak said: "I call on everyone to take these warnings seriously and not to travel there in the near future. I am sure that there will be a time when it will be possible to visit but now is not that time."