The long-range Grad rockets fired Monday were aimed at a crossing on the Israel-Egypt border, but landed in Egypt. The Islamic State has claimed in the past that it fired rockets at Israel from the Sinai.
Rocket alert sirens sounded in southern Israel on Monday, though no rockets were found to have landed in Israeli territory.
The Islamic State, or ISIS, said late Wednesday that the Israel Defense Forces responded to its missiles with the strikes on an ISIS position in the Sinai. The IDF does not respond to such statements.
In recent years, Israel has allowed Egypt to send extra infantry battalions into the Sinai Peninsula to fight Islamist terrorists. Under the terms of the 1979 Israel-Egypt peace treaty, Egypt must ask Israel for authorization before sending troops into the Sinai, which is supposed to remain demilitarized.