JERUSALEM — Israel's four-day-old air offensive in the Gaza Strip expanded to target Hamas government buildings on Saturday, and Palestinian militants continued firing a torrent of rockets at civilian areas in southern Israel, as both sides stepped up diplomatic efforts to win support.
Israeli airstrikes over Gaza accelerated to nearly 200 early in the day, including one hit that reduced the offices of Hamas Prime Minister Ismail Haniyeh to a smoldering concrete heap. That strike, along with others on a police headquarters and smuggling tunnels along the strip's southern border with Egypt, raised questions about whether Israel had broadened its mission to including toppling the Hamas government that rules Gaza.
Just before sundown, Hamas said it had shot an Iranian-made Fajr-5 rocket at Tel Aviv, and air raid sirens sounded in that city for the third day in a row. The Israeli military said its newly deployed missile defense battery intercepted the rocket before it landed in the populous coastal city.
Even as airstrikes pounded Saturday morning, the foreign minister of Tunisia's Islamist-led government, Rafik Abdessalem, arrived in Gaza with a delegation, underscoring Hamas' newfound credibility in a region dramatically altered by the Arab Spring. Abdessalem expressed outrage at what he called Israeli "aggression" and pledged to unite with other Arab countries to end the conflict.
In Cairo, Egyptian President Mohammed Morsi, whose prime minister visited Gaza on Friday, held meetings with Turkey's prime minister, Recep Tayyip Erdogan, and the emir of Qatar, both Hamas supporters, to discuss what Morsi and other regional leaders have promised would be a more robust response to Israel's actions than during past conflicts.
Also in Cairo, the Arab League held an emergency meeting of Arab foreign ministers to discuss an Arab response to the conflict. Many participants called for Arab assistance to the Palestinians and a "reconsideration" of Egypt's peace treaty with Israel.
Israeli Prime Minister Benjamin Netanyahu, meanwhile, took his country's case to European leaders. In conversations with German Chancellor Angela Merkel and the prime ministers of Italy, Greece and the Czech Republic, Netanyahu argued that "no country in the world would agree to a situation in which its population lives under a constant missile threat," according to a government statement.
The White House reiterated its support for the Israeli operation, which the military says is intended to stop rocket fire that has escalated in the four years since Israel last invaded Gaza to stunt attacks by Hamas, an Islamist movement that Israel and the United States consider a terrorist group.
The death toll in Gaza rose to 48 by Saturday evening, health ministry officials said. Three Israelis have been killed by rocket fire from Gaza since the operation began. An Israeli military spokesman said about 130 rockets were fired from Gaza at Israel on Saturday, 30 of which were intercepted.