Israel took the unusual step on Monday of barring its citizens from crossing into Egypt's Sinai peninsula, saying that the threat of attacks in the area inspired by "Islamic State" (IS) militant group and other takfiri groups was high.
Minutes after the ban was announced, the Israeli military said a rocket was launched from the Sinai and struck southern Israel, causing no injuries.
The ban will be in effect at the Taba crossing until at least April 18, the end of the Jewish holiday of Passover that begins at sundown on Monday, said a statement issued by the Israeli Prime Minister's Office.
Thousands of Israelis usually cross the land border with Egypt during the holiday to visit resorts and beaches along the Sinai Red Sea coast.
Egypt declared a three-month state of emergency on Sunday after two bombings of Coptic churches — one in Alexandria and one in the Nile delta city of Tanta — killed more than 40 people. IS claimed responsibility for both incidents and warned of future attacks.
In the thinly populated Sinai, an Islamist insurgency has gained pace since Egypt's military toppled President Mohamed Mursi of the Muslim Brotherhood in 2013, and militants have even carried out deadly cross-border attacks on Israel in recent years.
Militants in the Sinai aim, the statement said, "to carry out terrorist attacks against tourists in the Sinai, including Israelis, in the immediate future."
The statement urged Israelis already in the Sinai to return home immediately, reiterating a travel advisory that Israel's Anti-Terrorism Directorate issued on March 27.
Israel signed a peace treaty with Egypt in 1979.