Hezbollah Strikes Israeli Convoy With Anti-Tank Missile; at Least 3 Dead

Dead include Israeli soldiers and soldier with U.N.; other Israelis wounded.

JERUSALEM — -- An Israeli military convoy was struck by an antitank missile along the Lebanese border Wednesday, killing two Israeli soldiers and wounding at least seven, according to statements by the Israel's military. A Spanish soldier serving with the United Nations along the border inside Lebanese territory was also killed.

It’s the most serious escalation on this border in years, the attack taking place in the contested area called Shebaa Farms, or Mount Dov, as it’s called in Israel in the Israeli-occupied Golan Heights. Both Syria and Lebanon lay claim to that portion of land along the border.

Shortly after the attack Wednesday morning, the Lebanese militant group Hezbollah officially claimed responsibility, saying it was carried out by the “heroic martyrs of Quneitra” brigade, a reference to the six Hezbollah fighters and Iranian general killed by a suspected Israeli strike in Quneitra, Syria, on Jan. 18.

Israel was expecting a response by Hezbollah, but as with any conflict in the region, there are fears that it could escalate into an all-out conflict.

Speaking on a conference call with international journalists on Wednesday, Israel Ziv, an Israeli reserve major general and former head of the army’s operations, described the situation in the north as a "very tricky and, I would say, flammable situation.”

“Israel has to contain it, to defend our interests, but not get drawn in” to those northern battlefields, Ziv said.Roughly an hour after Wednesday's initial attack, mortar shells landed near Mount Hermon in the Israeli-occupied Golan Heights and the IDF evacuated civilians from the area. In a statement, the IDF confirmed that it retaliated by air and land against “Hezbollah operational positions."

“We have responded to Hezbollah’s escalation,” IDF spokesman Peter Lerner tweeted. He added later, “we reserve the right to respond further against Hezbollah.”

The United Nations and the Spanish embassy in Beirut confirmed to ABC News that a Spanish soldier for the U.N.'s monitoring body UNIFIL was killed during the shelling while at his post along the border. A Spanish medical team that rushed to the post from a nearby base was unable to save him, an embassy official said.

The prime minister of Spain tweeted his condolences.

Wednesday's fighting came after two rockets fired from Syria landed in the Israeli-occupied Golan Heights on Tuesday. They landed in open areas and didn't hurt anyone but Israel quickly responded by firing artillery into Syria. Just before midnight, Israel struck again, hitting Syrian Army artillery positions, the IDF said.

After Wednesday's attack, Israeli Prime Minister Benjamin Netanyahu rushed to Tel Aviv from southern Israel for an emergency security meeting.

“We will not allow terror elements to disrupt the lives of our citizens and threaten their security," he tweeted. "We will know how to respond with force to whoever challenges us.”

Speaking earlier Wednesday at an event in the southern city of Sderot, Israel, Netanyahu struck a similar tone.

"To anyone who is trying to challenge us on the northern border, I suggest looking at what happened here, not far from the city of Sderot, in the Gaza Strip,” he said. "Hamas was dealt its heaviest blow ever since its founding, and the Israel Defense Forces is prepared to act forcefully in all areas.”

ABC News' Molly Hunter is in Jerusalem. ABC News' Alexander Marquardt is in Beirut.