The Israeli air force attacked targets in the Gaza Strip, following rocket fire from the Palestinian territory into southern Israel, sources from both sides of the conflict said.
"In response to the numerous rockets launched at Israel in the past several the hours, IAF [Israeli air force] aircraft targeted terrorist infrastructure including 2 weapon storage facilities in the central Gaza Strip and a rocket launch site in the southern Gaza Strip. IAF pilots reported accurate strikes on the targets," the army said in a statement.
Palestinian witnesses said the air raids, which caused no injuries, hit uninhabited sites belonging to the radical Islamic Jihad movement, which is currently feuding with the Islamist Hamas Gaza rulers.
Late Sunday 2 Palestinian rockets landed in southern Israel, without causing any damage or injury, according to Israeli military sources.
Two other rockets were intercepted by Israel's "Iron Dome" defence system, the army said.
It said Hamas were "accountable" for the rocket attacks, although no group claimed responsibility.
The Kerem Shalom goods crossing, reserved for trade between Israel and the Gaza Strip, will be closed until further notice following the attacks, the army added.
Speaking to public radio on Monday morning, head of the parliamentary foreign and defence committee Avigdor Lieberman said Israel should consider reoccupying the Gaza Strip and "cleansing" it.
"In another 2 years, Hamas will have thousands of rockets that could reach Tel Aviv and beyond," said the former foreign minister who is a member of Prime Minister Benjamin Netanyahu's Likud-Beitenu party. "We will find ourselves in a reality that they have all kinds of aircraft and rockets, Hamas is not losing time."
"Since Hamas has not intention to recognise Israel or coexist in peace or accept the Jewish presence in Israel, there will be no alternative and eventually Israel will have to seriously consider the possibility of occupying all of the Strip and carrying out a serious cleansing," he said.
Israel seized Gaza from Egypt in 1967, and in 2005 unilaterally withdrew from it.
"It's not simple, but on the long run there will be no choice if we want to see a different reality there," Lieberman said of Gaza.
The latest exchange of fire came as a row erupted between Hamas and the radical Islamic Jihad movement in the Gaza Strip.
Islamic Jihad severed contacts with Hamas on Sunday after a commander in its military wing, Raed Jundiya, died of wounds sustained in a police shooting, a leader of the radical group told AFP.
Islamic Jihad claims to have 8,000 fighters in its military wing, making it the second largest armed group in Gaza behind only Hamas itself.
On Monday, a spokesman for Gaza's Prime Minister Ismail Haniyeh announced that the Hamas government was expanding the investigative commission looking into Jundiya's death to include beyond the Hamas interior ministry members of the Islamic Jihad and Jundiya's family.
In recent months there has been an uptick in rocket fire on southern Israel after more than three months of complete quiet following a deadly confrontation last November which ended with an Egyptian-brokered truce.
Last week on two occasions Gaza militants fired projectiles at Israel which however landed within the Gaza Strip.
