Attackers mounted at least three separate strikes on Israeli civilians and soldiers around the popular Red Sea resort of Eilat on Thursday, in what the country’s defense minister called a “grave terrorist incident.” Seven Israelis were reported killed and 20 wounded, and the military said seven attackers were killed.

The Israeli military said the attacks originated in Gaza, and were the result of increased lawlessness in eastern Egypt following the country’s revolution. That would make them the first violent attacks inside Israel that were directly tied to the political upheaval in the Arab world this spring.

The first attack took place around midday in a sparsely populated desert area close to Israel’s border with Egypt on the Sinai Peninsula, as gunmen opened fire on an Israeli bus. Shortly after that, the Israeli military said, assailants fired an anti-tank missile at a private car and, in a third attack, detonated a roadside bomb next to Israeli soldiers patrolling near the border with Egypt.

“This is a grave terrorist incident in a number of locations,” said the defense minister, Ehud Barak. “The incident reflects the weakness of Egypt’s hold over Sinai and the spread of terrorist elements. The source of the terrorist attacks is in Gaza, and we will act against them with full force and determination.”

A spokesman for the Israeli ambulance service said seven Israelis were killed but he could not say how many were civilians and how many were soldiers. As for the attackers, Israeli forces were “still sweeping the area, and there are still shots fired,” said Ofir Gendelman, a spokesman for Prime Minister Benjamin Netanyahu.

The gunmen in the bus attack, who fired from a car, sped away from the scene afterward, and Israeli forces and helicopters were chasing them. The military spokesman said there was initial contact between the Israeli forces and the attackers.

Television pictures from the scene showed the bus, which had come to a stop near a roadblock at Netafim, a few miles northwest of Eilat, with shattered windows and bullet holes in the front. Passengers said they saw three gunmen wearing blue overalls. The bus was traveling from the southern Israeli city of Beersheba to Eilat, and was carrying soldiers and civilians.

The Israeli military shut down two highways around the town of Eilat after the attack, complicating efforts to report from the scene. Reuters retracted an earlier bulletin describing an explosion in Beersheba.

Israeli analysts speculated that the gunmen in the bus strike may have come from Gaza, traveled south via Sinai and crossed the border from there into Israel, or that they originated in the Sinai.

The Sinai has become notorious for lawlessness, and Israel has repeatedly issued stern warnings to tourists about the risk from Islamic extremists operating in the desert region.

Egyptian news media, citing state television, said security officials whom it did not name denied that the attacks in Israel on Thursday were mounted from Egypt.

In recent days, Egyptian soldiers have been sent to crack down on lawlessness in the northern Sinai, following an attack on a police post there. The region is dominated by Bedouin tribes and is a hotbed of illegal weapons sales, smuggling and other activities. A pipeline that runs through the area, carrying natural gas to Israel from Egypt, has been disrupted by five bombings in recent months.

In early 2007, a Palestinian walked from Egypt across the border into Israel, hitched a ride from an Israeli motorist and then blew himself up inside a bakery in Eilat, killing three.