Israel called up 33,000 reserve soldiers and may bolster infantry brigades, intensifying its military campaign against Hamas as a rocket fired from Gaza seriously wounded an Israeli civilian for the first time.

Two others were hurt today when the rocket hit a gas station in Ashdod, in the south, police said in a text message. Rocket fire also came from southern Lebanon for the first time in the four-day offensive, in which 100 Palestinians are said to have been killed.

Israel already has deployed three infantry brigades near the Gaza Strip border, army spokesman Lieutenant-Colonel Peter Lerner said in a phone briefing. About 194 rockets have been launched at Israel in the past 24 hours, he said, adding that the “Iron Dome” defense system has a 90 percent success rate in intercepting rocket fire.

World leaders have sought to steer Prime Minister Benjamin Netanyahu away from sending ground forces into Gaza. Palestinian President Mahmoud Abbas told Hamas to stop its attacks to end the bloodshed in a rare public rebuke that may further strain their political alliance. Abbas has also denounced the abduction of three Israeli teenagers, whose killing last month Israel blames on the militant group, which neither confirms nor denies involvement.

Netanyahu remained vague yesterday about Israel’s plans, saying in a televised address that a “difficult, complex” battle lies ahead, without elaborating. The Palestinian territory is surrounded by land, air and sea forces awaiting the prime minister’s word to move in.

President Barack Obama spoke by phone with Netanyahu and offered to “facilitate a cessation of hostilities,” according to a White House statement. UN Secretary-General Ban Ki-moon told the Security Council the threat of a ground offensive is “still palpable — and preventable only if Hamas stops rocket firing.”

The attack in Ashdod sent thick plumes of smoke into the air and sparked a fire that took firefighters an hour to extinguish, Eli Cohen, spokesman for southern district fire and rescue service, said by phone.

“It was a miracle, an even worse disaster was averted,” he said.

Earlier, sirens wailed in Haifa, one of the biggest cities in the north.

The Al-Qassam Brigades, the armed wing of Hamas, today asked foreign airlines to suspend flights to Ben Gurion airport in Tel Aviv because of risks. When asked about that on Israel Radio, Internal Security Yitzhak Aharonovitch said the government is aware the group is aiming at various locations.

Sirens sounded at the airport today and takeoffs and landings were stopped for nine minutes, said Ofer Lefler, spokesman for the Israel Aviation Authority. It was the second time that’s happened since beginning of the operation.

Israel aircraft stepped up weeks of strikes on Gaza on July 8 after rocket fire grew heavier, reaching farther into Israel than ever before. Israel has struck about 1,100 targets in Gaza, including tunnels militants dug under the border with Israel, their homes, rocket launchers, command centers and training camps, according to the army.

At least 550 rockets have been fired from Gaza. In addition to the deaths in the coastal strip, there have been 660 injuries, emergency medical services chief Ashraf al Qedra said by phone today.

Israel’s benchmark TA-25 index fell 0.3 percent at the close in Tel Aviv yesterday. The shekel was little changed at 3.4305 to the dollar.

The rocket fire from Lebanon struck near the border and the Israeli military responded with artillery fire, Lerner said. The Lebanese army said three rockets were fired and the Israelis retaliated by firing about 25 artillery shells. Lebanese troops and UN peacekeepers later found two unexploded rockets in the area.

Lebanon’s official National News Agency said one of those who fired into Israel was injured and authorities are looking for him in hospitals. Southern Lebanon is a stronghold of the Shiite militant group Hezbollah.