koijemala: Tensions, violence increase along Israel-Gaza border

Tensions are escalating as fighting between Israelis and Palestinians increases. NBC's Martin Fletcher and Ayman Mohyeldin report.

By Lawahez Jabari, NBC News

Updated 2:24 p.m. ET: Three Israeli civilians were killed and six injured on Thursday as rockets were fired from Gaza into Israel, including a long-range missile that struck a suburb eight miles south of Tel Aviv.

Israel launched numerous airstrikes across the Gaza Strip as the region's military showdown lurched closer to all-out war.?Fifteen Palestinians have been killed and 100 injured in Gaza since Wednesday, Reuters reported.

The long-range missile, which landed in an open area?outside Rishon Lezion, causing no injuries or damage,?was thought to be the first of its kind launched from Gaza.?Air raid sirens were later sounded in Tel Aviv, at about 6.30 p.m. local time (11:30 a.m. ET), NBC News reported.

NBC's John Ray reports from a funeral procession for Hamas' Ahmed Jabari in Gaza City, where Palestinians vow to avenge the deadly Israeli strike.

Israeli troops were moving toward the Gaza border, heightening worries by Palestinians about a possible ground invasion, NBC's Martin Fletcher reported. Reservists were also ordered to report for duty by the defense minister.

"There is a great sense of anxiety and tension in the air here," NBC's Ayman?Mohyeldin reported from Tel Aviv. "People are very much worried about the ongoing operation. "There's no doubt from the perspective of the Palestinians this could possibly escalate even further."

In another sign of the growing fear of danger in Gaza, many humanitarian aid workers have evacuated, NBC News reported.

Israel's ambassador to the U.S., Michael Oren, did not rule out a ground operation in Gaza in an interview with NBC's Andrea Mitchell on Thursday.

"Nobody wants a ground operation, and we are going to try to avoid that," Oren said, "But, again, we're going to have to take all necessary means to defend our citizens against this flagrant aggression. "

Earlier Thursday, the funeral was held Thursday for Ahmed Jabari, the senior Hamas military commander, who was one of those killed in the Israeli Defense Force airstrikes.

Three Israelis were killed when their apartment building was struck by a rocket fired from the Gaza Strip, an attack that intensified tensions between Israel and Palestinian militants. The incident came after Hamas' top military commander and others were killed in a series of airstrikes by the Jewish state. NBC's Martin Fletcher reports.

The IDF said on its website?that the three people killed were civilians in the southern Israeli town of?Kiryat Malachi.

It added that 43 of the rockets from Gaza had been intercepted by its defense systems, and that it had targeted 156 "terror sites" in Gaza since the start of what it called "Operation Pillar of Defense."

"In the past 24 hours, 245 rockets have been fired from the Gaza Strip into southern Israel," it said.

Tsafrir Abayov / AP

An Israeli soldier throws a blood-stained table from an apartment building hit by a rocket fired from the Gaza Strip, killing three people in Kiryat Malachi, southern Israel, Thursday.

Hamas chief Khaled Meshaal on Thursday condemned the killing of Jabari.

"Men and women in Palestine, we will continue the resistance," Meshaal said at a meeting of Islamic leaders in the Sudanese capital Khartoum.

The United Nations Security Council held an emergency meeting late on Wednesday to discuss the Israeli assault. It called for a halt to the violence, but took no action.

Analysis:?Israel, Gaza slide closer to war neither side wants

Egypt officially requested on Thursday a full meeting of the Security Council to discuss what it described as Israeli aggression, and withdrew its ambassador from Israel.

Egypt's President Mohammed Morsi said in a televised address to the nation Thursday that Israel's attacks on the Gaza Strip were "unacceptable" and would lead to instability in the region.

Morsi said he had discussed "ways to reach calm and end the aggression" in a telephone conversation with U.S. President Barack Obama.

Israeli leaders indicate that a new offensive against Islamic militant commanders is underway. NBC's Martin Fletcher reports.

Hamas is affiliated to the Muslim Brotherhood which now controls Egypt, Israel's most powerful Arab neighbor and a crucial partner in the 1979 peace treaty that stands between fragile stability and regional chaos.?The Muslim Brotherhood on Thursday called for all ties with Israel to be severed.

PhotoBlog: Deadly day along Israeli-Gaza border, after Israel kills Hamas military chief

Hamas has been emboldened by the Islamist rise to power in Egypt, viewing Morsi?as a "safety net" who will not permit a second Israeli thrashing of Gaza, home to 1.7 million Palestinians.?

Expecting days or more of fighting, Israel warned Hamas that all its men were in its sights and dropped leaflets in Gaza telling residents to keep their distance from militants and Hamas facilities.

Israeli Defence Force via YouTube

Video posted to YouTube by the Israeli Defence Force claiming to show its attack on a car in Gaza on Wednesday in which Ahmed Jabri, the head of Hamas' military wing, was killed. The video has not been independently verified by NBC News.

"The leaflets stress that Hamas is dragging the region toward violence, and that the IDF is prepared to defend the residents of the State of Israel until quiet is restored to the region," the military said in a statement.

Israel also warned its own citizens to stay off the streets.?

Israel kills Hamas military chief, 7 others in airstrike, officials say

The United States condemned Hamas, shunned by the West as an obstacle to peace, for its refusal to renounce violence and recognize Israel.?

The U.S. State Department on Thursday called for a de-escalation of the violence in the Middle East and placed the onus for that violence squarely on Hamas.

"There's one clear way to mitigate the tensions,? spokesperson Mark Toner said. ?That is for Hamas to stop its rocket attacks on Israel so we can de-escalate the situation and end the violence. That's the clearest path."?

Israel says it has already destroyed much of Gaza's longer-range rocket stockpiles.?Reuters reported that Hamas had claimed it had fired a 1.1 ton, Iranian-made Fajr 5 rocket at Tel Aviv, but there was no reported impact in the Israeli city.

Few in the Palestinian territory's largest urban area, Gaza City, came out following the call for dawn prayers on Thursday, and the only vehicles plying the streets were ambulances and media cars.?

About 400 angry mourners braved the streets, however, to bury Jabari, whose body was draped in the green flag of the Islamic militant Hamas movement. Some fired guns in the air and chanted, "God is Great, the revenge is coming."

When the body was brought into a mosque for funeral prayers, some tried to touch or kiss it. Others cried.?BBC producer Paul Danahar posted pictures of the scene outside the mosque on Twitter.

President Barack Obama also spoke to Israel?s Prime Minister Benjamin Netanyahu as well as Morsi on the telephone late Wednesday.

A White House spokesman said Obama reiterated to both leaders the United States' support for Israel's right to self-defense, and agreed with Morsi on the importance of working to de-escalate the situation.

Reuters, NBC News' Catherine Chomiak and Alastair Jamieson contributed to this report.