Palestinian militants fired three Grad rockets toward the southern Israeli city of Be'er Sheva on Thursday morning, after the Israel Air Force launched several strikes on the Gaza Strip overnight.
Early Thursday, a Gaza rocket landed near Netivot in southern Israel and shortly afterward, three Grad rockets were fired toward Be'er Sheva.
Islamic Jihad has denied any involvement in Thursday's rocket fire.
Despite an Egyptian-brokered cease-fire between the sides which went into effect early Tuesday morning, Palestinian militant groups continued to fire rockets sporadically into Israel on Tuesday and Wednesday.
Five cities in southern Israel - Be'er Sheva, Ashdod, Ashkelon, Kiryat Malakhi and Gan Yavneh - decided to cancel school on Thursday.
On Wednesday night, three Grad rockets were fired toward Be'er Sheva and Ofakim in southern Israel. Two were intercepted by an Iron Dome anti-missile battery, while the third landed in an open area near Ofakim. There were no casualties or damage to property, altough several suffered from shock.
In response, Israel carried out two air strikes on militant targets in Gaza early Thursday morning, according to the IDF Spokesman.
No Palestinian organization had claimed responsibility for the rockets, but the IDF believes they were launched by one of Gaza's small, radical Islamist factions. All of the factions' leaders committed to the truce in talks with Egyptian mediators.
Defense officials said they believe Hamas is not interested in a resumption of violence, and will therefore try to restrain smaller factions. However, they stressed that Israel will continue to carry out targeted killings of terrorists if it receives intelligence warnings of a planned attack.
Earlier on Wednesday, Palestinians fired a mortar shell at the western Negev, but it apparently fell short and landed in the Gaza Strip.
"There's no magic solution to rockets," GOC Southern Command Tal Russo said on Wednesday during a visit to a high school in Omer. "There won't be a complete solution even if we embark on another round of fighting."
Speaking before the rockets were fired at Be'er Sheva, Russo added, "I don't know how long the quiet will hold. But if they violate the quiet, we have many tools. In this round, we didn't use all the tools at our disposal. There could be situations in which a larger operation is needed."
Prime Minister Benjamin Netanyahu was supposed to leave for Paris and Madrid on Wednesday, where he was meant to discuss Iran's nuclear program with French President Nicolas Sarkozy and the new Spanish prime minister, Mariano Rajoy.
However, despite the cease-fire declaration, Netanyahu canceled the trip due to the "security situation in southern Israel" - raising the question of whether he expects another round of fighting to erupt.