President Bush upheld Israel's right to self-defense Monday after its air strike in Syria following a deadly Palestinian suicide bombing.
A White House spokesman said Washington had told both Israel and Syria to avoid escalation as tensions rose in the Middle East.
In a new incident which heightened fears of conflict in the volatile region, security sources in Lebanon said Israel fired at targets across the border Monday. No one was hurt.
Israel denied the report, but an official from the U.N. peacekeeping force in Lebanon said one of its water trucks was hit by three bullets fired from inside Israel.
In Washington, a White House spokesman criticized Syria for "harboring terrorists" and Bush said he had told Israeli Prime Minister Ariel Sharon by telephone Sunday that Israel should not feel constrained in defending itself.
"I made it very clear to the prime minister, like I have consistently done, that Israel's got a right to defend herself, that Israel must not feel constrained in terms of defending the homeland," Bush said.
"However, I said that it's very important that any action Israel take(s) should avoid escalation and creating higher tensions," he said.
The air strike on an alleged training camp for Palestinian militants Sunday was Israel's deepest into Syria since the 1973 Middle East war.
The raid followed a Palestinian suicide bombing which killed 19 people at a restaurant in the city of Haifa Saturday, just before the solemn Yom Kippur fast day.
U.S. CRITICIZES SYRIA
"We urge both Israel and Syria to avoid actions that heighten tensions or that could lead to hostilities, but we have repeatedly told Syria that they need to stop harboring terrorists," White House spokesman Scott McClellan said.
Syria has asked the U.N. Security Council to condemn the Israeli raid. It urged Washington not to block its resolution.
The Islamic Jihad movement, which carried out the attack in Haifa, said Israel would pay a big price if it extended its conflict with Palestinian militants abroad.
But Beirut-based Islamic Jihad official Abu Imad al-Rifai said: "I think our response will remain first and foremost inside Palestine by virtue of our presence inside Palestine and the presence of our military forces inside Palestine."
Islamic Jihad regards Israel as being part of Palestine.
Political analysts doubt three years of Israeli-Palestinian conflict will trigger violence across the Middle East, but Israel now faces heightened tensions with Syria and Lebanon.
In Lebanon, an official with the U.N. peacekeeping force UNIFIL said no one was hurt in the shooting near the border with Israel.
"A UNIFIL water truck was hit by three bullets from the Israeli side," he said. "All our trucks are clearly marked."
A Lebanese security source had earlier said shots were fired from Israel into Lebanon and went over Lebanese cars on a road near the border. An Israeli army spokesman said: "The army did not attack any targets in Lebanon."
SYRIA APPEALS TO UNITED NATIONS
Syria called an emergency Security Council meeting Sunday but the United States, which has a veto on the council, said it would not support a resolution which condemned the Israeli raid but made no mention of the suicide attack. Russia, which also has veto power, said Monday the Syrian resolution could pass if it were balanced.
Syria wanted an immediate vote, but no action was expected on the resolution Monday.
"We hope the United States does not use the veto and that it practices its role as a superpower in preventing aggression and escalation," a Syrian Foreign Ministry official said, adding that Washington should help to douse tension in the Middle East.
The United States said the resolution had to go to the capitals of council members for study.
Israel, which came a to a halt for Yom Kippur, the holiest day of the Jewish calendar, said it did not intend to pick a fight with Syria but the air raid should serve as a warning for it to stop Palestinian militants operating on Syrian territory.
Syria denies links to "terrorist groups" but says it backs legitimate resistance to Israeli occupation. It says Palestinian militant groups only have media offices on its territory. (Additional reporting by Inal Ersan in Damascus)