The IAF strikes carried out early Monday morning targeted a weapons-storage site and four rocket-launch sites in the northern Gaza Strip and one rocket-launch site in the southern Gaza strip. A wounded Palestinian boy is wheeled into a hospital in Gaza City after an Israeli air strike (REUTERS/Ahmed Zakot) 
 
 Israel's air force pounded Gaza overnight with a series of raids which killed three people, raising the death toll to 21 in a wave of tit-for-tat violence that began with Israel's killing of a senior militant on Friday. The Palestinians last year won membership of UNESCO and say they could seek seats with other international agencies. One of seven rockets fired at the Eshkol Regional Council area overnight fell near a kindergarten, causing damage to a building. Another large southern city, Beersheba, was also victimized by rocket fire on Monday. JUST WATCHED Israeli airstrikes target Gaza Replay More Videos ... MUST WATCH Israeli airstrikes target Gaza 01:53 
 
 "It's a very difficult time for us," said Eti Ifrah, 23. "I am gravely concerned at the latest escalation between Gaza and Israel, and once again civilians are paying a terrible price," U.N. Secretary-General Ban Ki-moon said in a statement Monday. We hope parties concerned can stop firing immediately in order to avoid casualties of innocent civilians." Speaking at a press conference Monday in Gaza City, Abu Ahmad boasted his group had fired dozens of longer-range Grad rockets into Israel and a larger number of smaller short-range rockets. Three civilians and four militants were reported killed in Gaza on Monday, but Israeli and Palestinian officials offered different accounts of the violence. Wounded Palestinian children receive medical atttention at a hospital in Beit Lahia in the northern Gaza Strip following an Israeli air raid (MOHAMMED ABED/AFP/Getty Images) 
 
 Israel said Palestinian militants had fired a total of 180 rockets from the impoverished territory since the violence erupted, leaving four Israelis wounded. At least eight of the 31 rockets fired on Monday were intercepted by the Iron Dome rocket defense system, including several fired toward Ashdod.  Photo: YAAKOV LAPPIN 
 
 A Grad rocket fired from the Gaza Strip landed in the Gedera area on Monday, marking the northern-most point hit by terrorists in the current round of escalation that began Friday and has included the launching of some 200 rockets by terrorists targeting southern Israel. Palestinian Islamic Jihad said that two armed terrorists belonging to the organization were killed in IAF strikes, bringing the total number of Palestinians killed since hostilities began Friday to 20. An Israeli military spokeswoman said she was looking into the report. "Naturally, this led to another round with the Popular Resistance Committees, Islamic Jihad and other groups," Netanyahu said, naming Palestinian militant groups.
– With 23 Palestinians now dead in the latest Gaza conflict, the Middle East Quartet is meeting for the first time in six months in New York. Hillary Clinton, UN Secretary-General Ban Ki-moon, Russian Foreign Minister Sergei Lavrov, and EU diplomat Baroness Ashton will discuss the growing violence after Israeli air raids killed five more people, including three civilians and a pair of militants. Israel yesterday sought UN Security Council action over rocket attacks from Gaza. China has also weighed in on the situation, calling on Israel to halt its air raids, the Telegraph notes. Iran has labeled the raids "war crimes," urging international condemnation against the "abhorrent violation of human rights." Among the reported dead today was a 15-year-old boy, CNN reports, though Israel said it did not bomb the area where he was killed. For its part, Israel says its attacks "destroyed launching pits" for Iranian-built rockets. Some 31 more rockets were launched from Gaza today, bringing the total to more than 200, according to the Jerusalem Post.