WASHINGTON (Reuters) - The United States issued a fresh travel warning for Israel and the Palestinian territories on Friday to include American journalists and aid workers after a spate of violence and political instability.

In a notice that superseded a warning issued on January 17, the State Department urged U.S. citizens to be mindful of security when considering travel to Israel, to defer trips to the West Bank and avoid all travel to the Gaza Strip.

“American citizens in the Gaza Strip should depart immediately, a recommendation that the State Department has maintained and renewed since the deadly roadside bombing of a U.S. Embassy convoy in Gaza on October 15, 2003,” it said.

“This recommendation applies to all Americans, including journalists and aid workers.”

The statement noted “considerable violence” in the Gaza Strip in recent months between Palestinian factions and between Israeli security forces and Palestinian militants.

Palestinian President Mahmoud Abbas rejigged his government on Friday at the end of a state of emergency declared a month ago when the Islamist movement Hamas seized control of Gaza.

Hamas, which has militant and political wings, won an election victory 18 months ago that led to an international embargo of the Palestinian Authority.

The United States, a key ally to Israel, lists Hamas as a terrorist organization.

The travel warning said militant groups in Gaza continue to launch rockets against nearby Israeli towns and urged U.S. citizens to “exercise a high degree of caution” when going to restaurants, malls, places of worship and other public places.

“Israeli authorities are concerned about the continuing threat of suicide bombings,” it said. “The U.S. government has received information indicating that American interests could be the focus of terrorist attacks.”

The Quartet of international mediators -- the United States, European Union, United Nations and Russia -- is due to meet in Portugal on July 19 to discuss the prospects for Israeli-Palestinian peace.

The conference will be attended by Tony Blair, who stepped down as Britain’s prime minister in late June and was quickly named as the Quartet’s new envoy.