Fighting broke out along Israel's borders with Syria and Egypt today. Each side blamed the other for the almost simultaneous attacks.
It was the heaviest fighting since the 1967 six-day war, an Israeli military spokesman said.
Israel said that Syria attacked its troops along the Golan Heights and that Egypt attacked along the Suez Canal. Radio Damascus and Radio Cairo accused Israel of launching the attacks.
"It's war, it's war, not just a local incident," an Israeli military spokesman said in Tel Aviv. He reported heavy fighting on both the Syrian front and the Egyptian front.
There were reports of artillery exchanges along the canal, air raids and dog fights in the north and south and an attack by Israeli naval units on Egyptian positions on the Gulf of Suez, opposite the southern tip of the Israeli-occupied Sinai Peninsula.
Radio Cairo said Israeli forces tried to cross the Suez Canal, but were repelled, and said fighting took place in some sectors of the Israeli-occupied east bank of the waterway closed since the 1967 six day war. Cairo said its forces raised the Egyptian flag on Israeli-occupied territory.
In Jerusalem, Prime Minister Golda Meir's Cabinet met in emergency session and heard report from Defense Minister Moshe Dyan on the Egyptian and Syrian military buildups.
In New York, a spokesman said Israeli Foreign Minister Abba Eban conferred with Secretary of State Henry Kissinger. The Israeli ambassador to the UN, Josef Tekoah, also met with Sir Lawrence McIntyre of Australia, who is president of UN Security Council. But it was not immediately known whether he had requested an urgent session of the 15-nation council.
The fighting erupted shortly after an Israeli military spokesman announced that Israeli front-line troops had been put on the alert and reserves called up in what was described as a massive buildup of Egyptian and Syrian forces along the frontiers.
"Today at 2 p.m. local time Egyptian and Syrian forces opened an attack in the Sinai and Golan Heights," the Israeli announcement said. "Israeli forces are active against the aggressors."
The first Radio Cairo report said the Israelis attacked across the Gulf of Suez. It said several formations of warplanes attacked in the region of Zaafaran and Sikhna on the gulf.
At the same time Israeli gunboats were crossing the gulf, it said.
A Cairo broadcast 30 minutes later said Egyptian planes countered by attacking enemy bases and military targets in the occupied territories."
Radio Damascus said, "Israeli forces attacked our positions along the entire length of the cease-fire line. Our forces are returning the fire to silence it."
In the southern region of Lebanon, which adjoins the Israeli-occupied Golan Heights, witnesses said they saw dozens of Israeli and Syrian planes taking part in the aerial dogfights.
They said two of the planes crashed near the Lebanon town of Marjayoun, but their identity was not known.
The fighting erupted on Yom Kippur, Judaism's Day of Atonement, when Israel normally shuts down and traffic disappears from the streets. It is the holiest Jewish day.
The Israeli Army radio and national radio came back on the air -- they are normally shut down on Yom Kippur -- to bring the news to a public alarmed by three short blasts on the nation's air raid sirens.
"In the past two days there has appeared to be indications of an attack intention on the part of Syria and Egypt," the army radio said in an official communiqu