The United States is "extremely concerned" about violence on the border between Israel and Lebanon, and urges both sides to exercise "maximum restraint," State Department spokesman P.J. Crowley said on Tuesday.
The spokesman made his remarks hours after an Israeli officer, three Lebanese soldiers and a journalist were killed in an exchange of fire between Israeli and Lebanese soldiers at the border. Another Israeli officer was seriously hurt in the clash.
The rare cross-border skirmish represented the most serious violence along the frontier since a 2006 war. A second Israeli officer was seriously wounded, but was considered in stable condition.
Crowley said the United States was in touch with both governments. "We are trying to understand what happened ... Our greatest concern is that whatever did happen not be repeated. The region has enough tension as it is. The last thing that we want to see is this incident expanding into something more significant."
"We deeply regret the loss of life. We urge both sides to exercise maximum restraint to avoid an escalation and maintain the ceasefire that is now in place," he added.
Earlier Tuesday, Prime Minister Benjamin Netanyahu instructed the Israel Defense Forces to firmly respond to any future Lebanese fire.
The prime minister said after the incident that "Israel views the attack on IDF soldiers with extreme severity. This is a blatant violation of United Nations Security Council resolution 1701 (which ended the 2006 war between Israel and the Lebanese militia Hezbollah in southern Lebanon). I see the Lebanese government as directly responsible for this violent provocation against Israel."
"Israel responded, and will continue to respond in the future to any attempt to spoil the calm along the border and to harm the residents of Israel's north and the soldiers protecting them," Netanyahu added.
Defense Minister Ehud Barak also issued a statement, offering his condolences to the families of the Israeli casualties. Barak warned the Lebanese government to refrain from "further provocation" - referring to recent incidents in which the Lebanese army provoked Israeli forces at the border - and demanded that Lebanon launch an investigation into what he termed "a murderous act of terror."
The defense minister called upon UN peacekeepers in the region to fulfill their duty and take resolute action to prevent similar events, and to investigate this specific event.
Barak also said that he expected the international community to condemn the incident. "The IDF will continue to protect Israel's residents and its sovereign borders. Israel seeks peace – we proved it when we withdrew our troops in 2006 to beyond the international line. However, Israel will not tolerate any attack on its soldiers or its citizens within its sovereign territory," he said.