Israel will deploy tanks equipped with a new defense system along the Gaza border after Palestinian militants for the first time used a sophisticated, tank-piercing missile believed to be the most advanced weapon in their arsenal.

Israeli defense officials said the laser-guided Kornet came from Iran, the top backer of Gaza's Hamas rulers. Lebanon's Shiite Hezbollah guerrillas, also backed by Iran, used the Russian-made Kornets in their 2006 war against Israel, destroying or damaging several dozen Israeli tanks.

The Palestinian use of Kornet missiles, confirmed by Israel's military chief on Tuesday, marks a new milestone for Gaza militants, who have steadily built up their arsenal from a collection of crude, homemade rockets to include more menacing imported weapons.

Israel's answer is called Trophy, a first-of-its-kind Israeli-made system carried by tanks that is designed to shoot down missiles like the Kornet. The system, mounted on the side of a tank, detects an incoming missile and fires a projectile at it, destroying it, according to video of a test provided by the developer.

Violence has been escalating along the Gaza border in recent weeks. In his parliamentary testimony Tuesday, Israel's military chief, Lt. Gen. Gabi Ashkenazi, confirmed militants fired a Kornet missile for the first time earlier this month, and it penetrated an Israeli tank.

He called the missile "one of the most dangerous in the battlefield." Ashkenazi said. He said the missile did not explode inside the tank, and no one was hurt.

The Israeli defense officials, speaking on condition of anonymity because they were not authorized to discuss such matters publicly, provided no proof to support their claim that the laser-guided missile came from Iran. Also, it was not clear how it was delivered. Hamas controls a network of smuggling tunnels along Gaza's southern border with Egypt, though Egypt has pledged to crack down on smuggling.

Hamas has not confirmed or denied possessing the missiles.

In the wake of the recent attack, the military decided to move to the Gaza border dozens of tanks equipped with the Israel-developed Trophy system, which detects incoming projectiles and shoots them down before they reach armored vehicles. Production of the Trophy was stepped after the 2006 war against Hezbollah.

The Trophy has not yet been tried on the battlefield, though the Defense Ministry says it has been tested successfully against a variety of weapons, including Kornets.

Israel's volatile front with Gaza has been relatively quiet since an overwhelming military offensive against Palestinian militants two years ago. But there has been a surge in violence in recent weeks, with militants firing rockets and mortars into Israel and Israel responding with airstrikes.

Israel's ambassador to the United Nations, Meron Reuben, filed a complaint to the Security Council and to U.N. chief Ban Ki-moon on Tuesday, calling the rocket attacks a violation of international law and warning that Israel "will continue to exercise its right to self-defense."

He urged the international community to send a "clear and resolute message" against the militant attacks and to give "appropriate attention to the smuggling of arms into Gaza."

Ban's U.N. representative, Robert Serry, condemned indiscriminate rocket and mortar attacks and acknowledged Israel's right to self defense. He also urged Israel to "exercise maximum restraint" to prevent civilian casualties.

The Kornet — made in Russia and sold widely overseas — is the most advanced weapon believed to be in the hands of Gaza militants.

In use since the mid-1990s, the Kornet is capable of penetrating armor up to four feet (1,200 mm) thick and has a range of about almost four miles (5.5 kilometers). It carries a warhead of 22 pounds (10 kilograms).

Armed groups also possess rockets capable of traveling up to 70 kilometers (40 miles), putting the Tel Aviv metropolitan area in their range.

The U.S. and Russia are developing similar systems, but the Israeli one is believed to be the first to be deployed on the battlefield.