At least 687 Palestinians have been killed as Israel continued bombarding Gaza for the sixteenth day in a row, while fighting between Israeli troops and Palestinian militants was briefly suspended Wednesday in several flashpoint areas of the Strip to allow convoys of ambulances to retrieve the wounded.

Amid the ongoing violence, Hamas rejected a ceasefire to end 16 days of deadly fighting unless the blockade on the Gaza Strip is lifted, its chief Khaled Meshaal said in Doha.

The U.S. Federal Aviation Administration on Wednesday renewed its ban on American flights to Tel Aviv for another 24 hours, citing the "potentially hazardous situation" in Israel and Gaza.

It first imposed the ban on Tuesday, then renewed it at 1615 GMT with a Notice to Airmen, or NOTAM, that it said would be updated "within 24 hours."

The cancellation of European and U.S. flights to Israel due to rocket fire is further harming tourism in a region already paying for fierce fighting in Gaza, experts say.

But while the hospitality trade and small businesses are suffering, the broader Israeli economy is unlikely to be affected by the conflict with Hamas, in which more than 1,700 rockets and mortar shells fired from the Palestinian territory have so far hit southern and central Israel, they say.

Hamas said Wednesday that the suspension of international flights to and from Israel over security concerns about Gaza rocket fire was a "great victory."

"The success of Hamas in closing Israeli airspace is a great victory for the resistance, and is the crown of Israel's failure," Hamas spokesman Sami Abu Zuhri said in a statement.

The March 14 forces on Wednesday noted that the roadmap proposed by al-Mustaqbal movement leader MP Saad Hariri is “the most suitable” for Lebanon's endurance in the face of the current developments, stressing that the election of a new president has become “more than necessary.”

“In the face of the rapid developments in the region, from the battered Gaza that is standing tall against the Israeli killing machine to Iraq that is reeling under the hammers of terrorism and dictatorship, not to mention Syria, the (March 14) General Secretariat underlines that the election of a new president according to the Constitution and the Lebanese political system's mechanisms has become more than necessary to foil the impending threats,” it said.

Progressive Socialist Party leader MP Walid Jumblat on Wednesday lashed out at the rulers of Arab countries and their stance on the relentless Israeli assault against the Gaza Strip, noting that “the human remains of martyrs will fire back at them all.”

Jumblat also blasted the stances of Russia, the United States, Germany, Iran and France.

Airlines blocked flights to Israel Wednesday after a Gaza rocket struck near airport runways, as the U.N. chief urged an end to a conflict that has killed 639 Palestinians and 31 Israelis.

As the violence entered its 16th day, neither Israel nor Islamist movement Hamas appeared willing to end hostilities, despite days of diplomatic efforts to coax them into a truce.

A rocket fired from Gaza hit north of Tel Aviv's Ben Gurion airport on Tuesday, police said, prompting U.S. and European airlines to suspend flights to and from Israel.

"A house was damaged in a rocket strike in the Kiryat Ono Yehud region, several kilometers (miles) from the airport," police spokeswoman Luba Samri told Agence France Presse.

Al-Mustaqbal parliamentary bloc on Tuesday announced that it will organize a sit-in Wednesday to denounce the Israeli assault on Gaza which has killed more than 600 people until the moment, as it warned of “an attempt to blow up the situations in Tripoli.”

Condemning the Israeli “enemy's hostility, barbarism and brutal attacks, which were also committed in the past against Gaza, Lebanon and unarmed innocents in several Palestinian regions,” the bloc hailed “the endurance of the Palestinian people and the valor of the Palestinian resistance's heroic fighters.”

The U.N. agency for Palestinian refugees said Monday the number of people seeking refuge at its sites in Gaza to escape a two-week-old Israeli offensive on the enclave has soared to more than 100,000.

"This is a watershed moment for UNRWA, now that the number of people seeking refuge with us is more than double the figure we saw in the 2009 Gaza conflict," climbing to above 100,000, the agency's spokesman Christopher Gunness said in a statement.