Israel launches retaliatory air strikes after gunmen kill 7 (VIDEO)

Israeli jets have attacked the southern Gaza Strip after the government blamed Gaza militants for attacks on two buses in southern Israel that killed seven people.

The White House and Secretary of State Hillary Clinton denounced the militant attacks, in which gunmen armed with heavy weapons and explosives reportedly attacked buses, cars and an army patrol.

Israel has said that the Palestinian attackers crossed through Egypt's Sinai Peninsula, raising concerns that they might be exploiting instability in Egypt, the AP reports. 

Defense Secretary Ehud Barak called the attacks on a highway north of the Red Sea city of Eilat, near the Egyptian border‚ and later an army patrol — a grave terrorist incident, VOA reports.

Barak and other Israeli officials have asserted that the attackers came from the Hamas-ruled Gaza Strip. Hamas has denied involvement.

The Jerusalem Post reports that 7 people were killed in the attacks, while VOA quoted Israeli officials as saying 40 people were wounded.

(GlobalPost reports: "Several dead" in attack on Israeli buses)

Security sources told AFP that the gunfire in the initial incident appeared to come from the Egyptian side of the border.

The Israeli police spokesperson's office said "shots were fired at a bus on Highway 12 leading to Eilat from Mitzpe Ramon, near Netafim checkpoint," reported Al Jazeera.

Israeli radio said a vehicle carrying the gunmen followed the bus, before up to three men jumped out and opened fire with automatic weapons.

Most of the passengers on the first bus were said to be Israeli soldiers who are residents of Eilat. They were returning from their bases to go home for the weekend.

Israeli media reports say Israeli troops tracked and killed seven suspected attackers.

However, the Jerusalem Post reported that the Israeli Defense Forces and police were still searching area for terrorists.

Israeli military officials, meanwhile, said at least five people were killed in their retaliatory air strikes hours later: Reuters reports that the dead include a chief of the Popular Resistance Committee, an armed Palestinian faction.

USA Today reported Clinton's remarks on the attacks:

"The United States condemns today's attacks in southern Israel and all acts of terrorism in the strongest terms. These brutal and cowardly attacks appear to be premeditated acts of terrorism against innocent civilians. Our deepest condolences go out to the victims, their families and loved ones.

"This violence only underscores our strong concerns about the security situation in the Sinai Peninsula. Recent commitments by the Egyptian government to address the security situation in the Sinai are important and we urge the Egyptian government to find a lasting resolution.

"The United States and Israel are united in the fight against terror. We hope that those involved in the planning of these gruesome attacks will be brought to swift justice. We stand by Israel as our friend, partner, and ally — now and always."