The U.S. State Department is warning Americans traveling to Israel to use extreme caution in Jerusalem, avoid the West Bank and if already in Gaza, to get out immediately.

The new warning, issued Friday, is an update to a Jan. 17 warning issued to U.S. travelers to Israel. It states that Americans should be careful when traveling in West Jerusalem, the mainly Jewish-populated area frequently targeted by Palestinian terrorists. In addition, travelers are warned to avoid nightclubs, restaurants and other locations frequented by tourists.

"The U.S. government has received information indicating that American interests could be the focus of terrorist attacks. For that reason, American citizens are cautioned that a greater danger may exist in the vicinity of restaurants, businesses and other places associated with U.S. interests and/or located near U.S. official buildings, such as the U.S. Embassy in Tel Aviv and the U.S. Consulate General in Jerusalem," the warning reads.

In addition, the warning states that "large crowds and public gatherings should be avoided to the extent possible, and personnel should be alert to street vendors who sometimes aggressively harass tourists."

It notes that Americans have been asked to stay out of Gaza since October 2003, when a U.S. Embassy convoy was blown up.

The warning came one year and one day after the start of the Second Israeli War with Lebanon, sparked in the summer of 2006 when Iranian-backed Hezbollah terrorists kidnapped two Israeli soldiers along Israel's northern border with Lebanon. The 33-day war resulted in the deaths of 162 Israeli Defense Forces and Israeli citizens and more than 1,100 Lebanese civilians.

Though a ceasefire was enacted in August 2006, Islamic militants within Lebanon restarted fighting against the Lebanese army this summer.

On top of that, violence between competing Palestinian factions in the West Bank and Gaza last month forced the collapse of the Palestinian government, the ouster of Hamas, the top vote-getters in Palestinian elections a year earlier, and the propping up by the U.S. and Israel of Palestinian President Mahmoud Abbas and his Fatah Party.

President Bush is expected to reaffirm support for Abbas this week as international negotiators meet Thursday in Portugal to come up with a new plan for promoting peace between Palestinians and Israelis. Former British Prime Minister Tony Blair, who was named this week as the envoy for the Quartet of the U.S., Russia, European Union and United Nations, will be meeting with Secretary of State Condoleezza Rice on how to bring about stability through international assistance to the Palestinians.

On Saturday, Abbas installed a new government led by economist and moderate Salem Fayyad, who says he supports a two-state solution with Israel. Hamas called a special session Sunday to challenge the new government.

The State Department warning notes that Hamas "violently assumed control over Gaza in June 2007, making the already dangerous security situation there even more precarious," and militants continue to abduct westerners. On top of that, ongoing and occasional rocket attacks on Israel from Gaza have led to targeted attacks and ground incursions by the Israeli Defense Forces. Such attacks occasionally result in deaths and injuries of bystanders, who have also been caught in the middle of violence between "organized criminal elements."

The warning also suggests that foreigners may want to stay out of Israeli domestic politics as violence has marked some Israeli protests of settler relocation efforts.

"Some Americans and Europeans involved in demonstrations and other such activities in the West Bank have become involved in confrontations with Israeli settlers and the IDF. The State Department recommends that Americans, for their own safety, avoid demonstrations," the warning reads.

The State Department advisory also tells U.S. government employees that they must give notice to the consulate general’s security office when they travel in parts of the West Bank, and notes that other areas are off-limits altogether to U.S. government employees.