Israeli warplanes killed five militants in Gaza on Saturday, the second day of cross-border violence in which Palestinian fighters have fired dozens of rockets into Israel, both sides said.
Fifteen militants in the Gaza Strip have been killed since Friday, Hamas medics said. On Saturday, a gunman was killed in a vehicle near Gaza's border with Egypt.
Earlier in the day Israeli jets killed two gunmen on a motorcycle and two others in a pre-dawn attack, officials in Gaza said. The sounds of explosions and rocket fire reverberated across coastal Gaza and southern Israel early on Saturday and Israeli Defence Minister Ehud Barak said its air strikes would continue.
This round in the Strip is still far from over, he told reporters on a visit to the south of Israel, where around half a million people have been told to stay indoors and keep bomb shelters open.
Six people in southern Israel have been injured by rockets fired from Gaza. One man, a Thai worker, was reported to be in a serious condition.
Militant groups in Hamas-ruled Gaza vowed to exact revenge for Friday's killings and the Israeli military said more than 90 rockets had been fired at its territory since Friday, including 25 longer-range Grad rockets which Israel's Iron Dome missile interceptor system shot down.
Israeli Prime Minister Benjamin Netanyahu told local officials in towns under fire the Jewish state would continue to strike at all those who plan to attack Israeli citizens. He promised to supply additional missile defence batteries. Islamic Jihad and the Popular Resistance Committees (PRC), an armed faction largely independent of Gaza's Islamist Hamas rulers, said it had fired most of the rockets and mortars. The escalating violence drew appeals for a ceasefire from the United Nations, European Union, the West Bank-based Palestinian Authority and neighbouring Egypt, whose peace treaty with Israel has been tested by last year's toppling of Hosni Mubarak. EU foreign policy chief, Catherine Ashton, expressed concern. I urge all sides to re-establish calm, she said in a statement.
Richard Miron, a spokesman for U.N. Middle East envoy Robert Serry, called for both sides to exercise maximum restraint and condemned rocket firings at Israel.
MILITANT LEADERS KILLED IN CAR
The latest violence began on Friday when Israeli missiles destroyed a car in Gaza City, killing two militant leaders. One of them, Zuheir el-Qessi, head of the PRC, had been involved in plotting a cross-border attack from Egypt, Israel said.
Israeli media reported that Qessi had also been involved in the 2006 capture of Israeli soldier Gilad Shalit, was freed as part of a prisoner swap in October.
After darkness fell on Friday, further air strikes killed eight more militants in Gaza, Hamas Islamist officials there said. At least 12 civilians were among 26 wounded in the Israeli attacks, medics reported.
Israel said its attacks were on weapons manufacturing sites and militants preparing to fire rockets.
Egypt's Foreign Minister Mohamed Kamal Amr told state news agency MENA that his government was making crucial calls for an immediate end to this Israeli escalation to end bloodshed of our brothers. Hamas spokesman Sami Abu Zuhri called for Egyptian aid, saying Gaza was sinking in darkness and in blood.
In Gaza, thousands attended funerals for dead militants on Saturday, listening to speeches calling for revenge.
Gaza officials said Israeli troops opened fire on mourners at a burial for an Islamic Jihad militant attended by hundreds at a cemetery near the Israeli frontier fence, wounding four. Israel's military had no immediate comment on the incident.
Palestinian President Mahmoud Abbas urged restraint on both sides. He charged Israel was responsible for the serious deterioration but urged militants to avoid an escalation that could hurt efforts to renew talks for Palestinian statehood. Hamas, an Iranian-backed group that refuses to recognise Israel, did not claim responsibility for any missile attack on Israel, and there were no reported civilian deaths in Gaza, factors which may prevent the violence escalating. However, Israel says it holds Hamas responsible for any attacks launched from its territory. Hamas seized control of Gaza from Abbas's Fatah movement in a bloody 2007 coup, two years after Israel pulled its forces out of the territory it had captured in a 1967 war.
(Writing by Allyn Fisher-Ilan; Editing by Andrew Roche)