A Palestinian militant sneaked into Israel early Friday, opening fire on Israeli troops and killing one soldier, the military said. The troops fired back, killing the infiltrator in the incident that touched off fresh violence in the volatile border area, which had been mostly quiet since March.

The exchange began after the militant cut through the fence separating the Hamas-run Gaza Strip and southern Israel. The militant started shooting, prompting Israeli troops to respond, said Col. Tal Hermoni.

"The forces worked quickly and prevented a larger attack against the civilians in the area," Hermoni told Army Radio.

Later, the Israeli military said two rockets landed in southern Israel, causing no damage or injuries. Gaza health official Adham Abu Salmia said three people were seriously wounded when an Israeli airstrike targeted their vehicle.

The border has been mostly calm since the last escalation in March but shootouts such as Friday's and other violent incidents always raise concerns of a new Israel-Gaza flare-up.

No group took responsibility for the infiltration but in a text message sent to journalists, a group from Gaza, the Islamic Jihad, welcomed the attack. It identified the militant as Ahmad Nassar and called him a "martyr who has carried out the heroic attack."

In a statement, the military said it holds Hamas "solely responsible." It identified the killed Israeli soldier as Staff Sgt. Nitnel Moshiashvili, 21.

Residents of southern Gaza said they heard gunfire in the early morning hours and described hearing Israeli helicopters circling in the air. They also said tank shells were fired into Gaza that set fire to their fields.

An Israeli security official said air and ground forces were firing warning shots toward open areas in southern Gaza. He spoke on condition of anonymity because he was not authorized to discuss details of military operations.

Israel's border with Gaza has been relatively quiet since a three week war launched in December 2008 against the militant Hamas group, which rules the coastal strip.

Still, there have been some flare-ups between militants and Israeli soldiers guarding the border. The last major deadly incident along the Gaza border took place in March 2010, when two Israeli soldiers were killed in clashes. Israel's military also launches airstrikes in response to rocket fire by militants.

The last round of violence in March took place after Israel killed a militant leader, setting off four days of rocket barrages from Palestinian militants and airstrikes by the Israeli military.

That uptick left at least 24 Palestinians dead and disrupted the lives of about 1 million Israelis living in rocket range.

Hamas stayed out of the fighting in March, letting militants from the Islamic Jihad and Popular Resistance Committees carry out the attacks on Israel.

Hamas wants to avoid a full-scale offensive against Gaza, fearing a major conflict could undermine its control of the territory it violently overran five years ago.

But Israel considers Hamas responsible for all attacks from Gaza and notes that the militant group, which refuses to renounce violence against Israel, has continued to stockpile bigger and better weapons since the war.