Sept 7 (Reuters) - An Israeli army base in the occupied West Bank was vandalized on Wednesday with pro-settler graffiti daubed on its walls, a military statement said, in what appeared to be revenge for the dismantling of an unauthorized settler outpost.

Israel's military chief, Lieutenant-General Benny Gantz described the attack as Severe vandalism ... executed ... by a reckless, lawbreaking, extreme minority.

Israeli Defense Minister Ehud Barak said the action was a despicable act carried out by criminals.

Israeli media described the incident as the first so-called price tag operation targeting a military base, a reference to retribution militant settlers have said they will exact for any curbs on settlement in the West Bank.

On Monday, Israeli security forces demolished three structures in Migron, an unauthorized settler outpost. Hours later, a section of a mosque in a Palestinian village was set ablaze and the words price tag painted on its walls in an attack Palestinians blamed on settlers.

At the army base near the Palestinian city of Ramallah, unidentified vandals smashed windows and slashed the tyres of 13 vehicles, the military statement said.

Graffiti painted at the base criticized military officers and the Migron demolitions. YESHA, the main settlers' organization, condemned the incident and urged authorities to crack down on what it called a marginal group.

Some 500,000 Israelis live in the West Bank and East Jerusalem, territory captured in a 1967 war and home to 2.5 million Palestinians. The World Court views settlements Israel has built in the areas as illegal. Israel disputes this.

Palestinians hope to establish a state in the West Bank and Gaza Strip. Citing historical and religious links, the Israeli government refers to the West Bank by its biblical names, Judea and Samaria, and says a return to the pre-1967 frontier would leave Israel with an indefensible border. (Writing by Allyn Fisher-Ilan; Editing by Elizabeth Piper and Louise Ireland)