EILAT, Israel (CNN) -- At least seven Israelis were killed and more than two dozen others were injured in southern Israel Thursday when attackers fired shots at a civilian bus, assaulted Israeli soldiers, and fired mortars and an anti-tank missile, Israeli authorities said.
The assault occurred about 20 kilometers (12 miles) from the Israeli city of Eilat -- close to the Israeli-Egyptian border. Israeli soldiers exchanged gunfire with the assailants and killed seven militants, the military said.
Gaza," said Mark Regev, spokesman for Israeli Prime Minister Benjamin Netanyahu.
At least 25 people were injured in the attacks. The IDF said the casualties included civilians and soldiers.
Israel had been on heightened alert in the south of the country and an elite counter-terrorism unit was in the area, according to an Israeli government source who doesn't want to be identified because he cannot speak publicly about the matter. The counter-terrorism unit and Israeli soldiers responded to the attacks, the source said.
The incident began when shots were fired at a civilian bus traveling from Beer Sheva to Eilat, near the community of Netafim. Officials say it's likely there were both civilians and active-duty soldiers on the bus because it was the start of the weekend and soldiers might have been going on breaks to the Eilat area.
IDF spokesman Brig. Gen. Yoav Mordechai said that after the bus attack, explosives were used against an IDF force operating in the area. There were casualties in both incidents, the IDF said.
Mortars were fired toward Israeli troops near the Egyptian border, and an anti-tank missile was fired, Mordechai said.
"This is a serious terrorist attack in a number of locations," Israeli Defense Minister Ehud Barak said.
"The event reflects the weakening of Egyptian control over Sinai and the expansion of the activity of terrorist forces. The origin of these acts of terror is in Gaza and we will act against them in our full force and determination."
Netanyahu and Barak met to discuss the "grave attacks," the prime minister's office said. Barak was headed to the scene.
"In light of what's happening near Eilat, our deepest condolences go out to the victims, their families and loved ones, of what appears to be a brutal and cowardly act of terrorism in southern Israel," the U.S. Embassy in Tel Aviv said.
"We wish those injured a speedy recovery. The American people and the Israeli people stand united against terror and we hope that those involved in the planning of this gruesome attack will be brought to swift justice."
Eilat is a resort town on Israel's southern tip, near Egypt's Sinai border. It generally has not endured the kind of strife faced by other regions including the swath of southern Israel near Gaza -- the coastal Palestinian territory just south of the Jewish state along its west coast.
Across the border, the Egyptian army and police are cracking down in an "anti-terror" operation in the Sinai area of Egypt, state-owned media reported Tuesday, as reports emerged of Osama bin Laden's doctor surfacing in the area.
Police said they found hand grenades, machine guns, rocket-propelled grenades and ammunition in the operation that targets Sinai "terror cells" suspected in attacks on a gas pipeline to Israel and a police station in the border town of el-Arish.
One person was killed and 12 were arrested on Monday, the first day of the operation, said Hazem al-Maadawi, a police officer involved in the offensive.
Netanyahu told a Knesset committee recently that Egypt was having difficulty exercising its sovereignty over Sinai.
"What's happening in Sinai is that global terrorist organizations are meddling there and their presence is increasing because of the connection between Sinai and Gaza," Netanyahu said.
The Egyptian military presence in the demilitarized zone in Sinai -- which was created under the terms of the Camp David Agreement signed in 1978 between Egypt and Israel -- raises many questions.