Rocks were hurled near Tel Sheva on Tuesday at a tour bus carrying Israel's ambassadors on a study tour of the Negev.
The back window of the bus was broken, but nobody was injured. The ambassadors are in the country participating in the ministry's annual conference for its senior emissaries abroad.
Foreign Minister Avigdor Liberman, currently in London, issued a statement saying that this was "another illustration of the intolerable lawlessness of the Bedouin residents in the region that began with violations of the construction laws, and continues with violence and a refusal to accept the authority of the state."
Liberman said this "grave national problem" needed to be dealt with soon, "without blinking or apologizing." Deputy Foreign Minister Zev Elkin was on the tour with the ambassadors, but not on the bus that was hit by the rocks.