Israeli warplanes bombed an alleged Islamic Jihad (search) training base in Syria Sunday, attacking deep inside the neighboring country for the first time in three decades and widening its pursuit of Palestinian militants.

The airstrike -- a retaliation for a homicide bombing Saturday that killed 19 Israelis -- alarmed the Arab world and deepened concerns that three years of Israeli-Palestinian violence could spread through the region. Islamic Jihad claimed responsibility for Saturday's bombing, in which 55 people were wounded.

Washington urged both sides to show restraint -- but added pointed criticism of Syria (search), saying Damascus "must cease harboring terrorists and make a clean break from those responsible for planning and directing terrorist action from Syrian soil."

With little option for military retaliation, Syria turned for international support. On requests from Damascus, the U.N. Security Council and the 22-member Arab League (search) held emergency sessions Sunday as Syria's Foreign Minister Farouq al-Sharaa sought measures to deter Israeli "aggression."

Syria's U.N. Ambassador Fayssal Mekdad called on the council to adopt a resolution condemning the attack.

"Arabs and many people across the globe feel that Israel is above law," Mekdad said.

Israel's Ambassador Dan Gillerman defended the attack. He accused Syria of providing "safe harbor, training facilities, funding, [and] logistical support" to terrorist organizations.

Syria's draft calls for Israel to stop committing acts that could threaten regional security. It was unclear when the council would vote on the resolution or whether the United States would veto it.

Leaders of Islamic Jihad and other militant groups are based in Syria, but Jihad on Sunday denied having any training bases there. Syrian villagers near the targeted site said the camp had been used by Palestinian gunmen in the 1970s but was later abandoned -- and was now only used by picnickers and other visitors to its spring and olive groves.

The raid was a dramatic new tactic for Israel in its attempts to stop Palestinian militants. Closures, assassinations and military strikes into Palestinian areas have failed to stop homicide attacks, and Washington strongly opposes expelling Palestinian leader Yasser Arafat as Israel has threatened.

Israel said the bombing signaled it would pursue militants wherever they found support -- and it added an accusation that Iran also backs Islamic Jihad. "Any country who harbors terrorism, who trains [terrorists], supports and encourages them will be responsible to answer for their actions," government spokesman Avi Pazner said.

In the West Bank, Palestinian leader Yasser Arafat (search) declared a state of emergency and installed an emergency Cabinet with Ahmed Qureia (search) as prime minister. The hasty action was an apparent attempt to deflect possible Israeli action against Arafat following the homicide bombing since Israel has threatened to expel him.

The leader of Islamic Jihad, Ramadan Shallah, told Dubai-based Al-Arabiya TV that the Israeli attack was "a grave development that exceeded all rules of the game." He also warned Israel that the homicide bombing "will not be the last resistance operation" committed by his group.

In Egypt, the Arab League condemned the Israeli attack. It said the bombing "exposes the deteriorating situation in the region to uncontrollable consequences, which could drag the whole region into violent whirlpool."

The strike was launched just hours before the start of Yom Kippur (search), the holiest day on the Jewish calendar. It also came on the eve of the anniversary of the 1973 war between Israel and Syria, when Israel fought off a Syrian attack aimed at reversing Israel's 1967 seizure of the Golan Heights, a strategic border plateau. Sunday marked Israel's first military action deep in Syria since 1973.

The attack hit several targets at the Ein Saheb camp northwest of Damascus, Israeli security officials said. Hours later, plainclothes security officials banned journalists from approaching the camp. Dense trees blocked the site from view.

Bush administration officials said Israel had not informed Washington in advance of its retaliatory strike.

Raanan Gissin, adviser to Israeli Prime Minister Ariel Sharon (search), said the base was financed by Iran and used by several terrorist organizations, including Hamas and Islamic Jihad.

Undated footage said to be from the camp, taken from Iranian TV and released by the Israeli military on Sunday, shows a military officer conducting a tour of the camp. Hundreds of weapons, including grenades with Hebrew markings apparently captured from Israel, were displayed in one room. Underground tunnels were packed with arms and ammunition.

Another group, the tiny Syrian-based Popular Front for the Liberation of Palestine-General Command said it once used the camp, 14 miles northwest of Damascus, but that it is now deserted. A civilian guard was injured in the air strike, the group said.

However, a senior Popular Front member, speaking on condition of anonymity, acknowledged that there is close cooperation between his group, Islamic Jihad, the militant group Hamas, and the Lebanese guerrilla faction Hezbollah. All four train together, mostly in Lebanon, but also in Syria, he said.

In an understanding with the Syrian government, Hamas and Jihad leaders have been careful in recent months to give statements from Lebanon to avoid the impression that they still operate from Damascus.

Still, Syrian President Bashar Assad (search) is on the defensive, with the United States accusing him of hosting extremist groups and sponsoring terror.

Assad, after meeting with Secretary of State Colin Powell (search) in May in Damascus, indicated that his government had closed certain offices of Palestinian militant groups. However, last weekend, U.S. National Security Adviser Condoleezza Rice (search) said Syria needed to do more.

It seemed unlikely Syria would retaliate. It has 380,000 active duty soldiers, but Israel holds a commanding technological edge. Israel is more worried about Syria's growing missile program and its ability to launch chemical and poison weapons into Israel's cities.

Egypt, Jordan and Lebanon -- three Arab countries border Israel -- condemned the air strike. "It can drag the whole region into a circle of violence," said Jordanian Foreign Minister Marwan Muasher.

Britain, the leading U.S. ally in the United Nations Security Council, was more critical of Israel. Britain's U.N. Ambassador Emyr Jones Parry said, "Israel's action today is unacceptable and represents an escalation."

"Israel should not allow its justified anger at continuing terrorism to lead to actions that undermine both the peace process and we believe Israel's own interests," he said.

The United States, trying to put its peace efforts back on track, has in past days appeared willing to give Qureia a chance, and any Israeli action against Arafat could force Qureia's immediate resignation and cause chaos in the Palestinian areas.

The Associated Press contributed to this report.