Israeli tanks are gathering on the border with Gaza.
Their presence adds weight to the rumours that preparations are underway for a ground invasion.
Israeli Prime Minister Benjamin Netanyahu told a cabinet meeting on Sunday that his soldiers were “ready for anything.”
The diplomatic focus, meanwhile, is on Cairo.
Israel has made no comment on Egyptian claims that a senior Israeli official has arrived for talks.
France’s Foreign Minister Laurent Fabius is in Tel Aviv to help with the diplomatic effort. “We are very worried because the situation is escalating and the tension is increasing. We, the French, as a force of peace, want to help bring about a de-escalation.”, he told reporters.
Fabius says he has spoken with representatives from Egypt, Turkey and Qatar as well as UN Secretary General Ban Ki-moon, who is due in Cairo on Monday.