By Mark Heinrich

BAQA AS SHARQIYA, West Bank, Nov 20 (Reuters) - For Palestinians trapped by a vast Israeli barrier, George W. Bush's rebuke of Israel for "humiliating" them had a drearily familiar ring of big talk but no hint of action.

In Baqa as Sharqiya, a market centre turned overnight into a dead-end enclave by the barricade Israel is erecting inside the occupied West Bank, townsfolk said on Thursday Bush's prod at his close ally would bring them no relief.

Bush urged Israel on Wednesday not to prejudice chances for peace negotiations by building "walls and fences".

"On the face of it, this was an important message from Bush -- that you cannot get peace by building fences and walls and degrading a whole nation," said Mayor Moayad Hussain.

"But we have heard only many words, we've never seen action by the Americans, to stop Israel slowly but surely reducing our world to an open-air prison," he said. "We cannot work or trade. We cannot even visit relatives a few km (miles) away."

The downbeat people of Baqa as Sharqiya are among tens of thousands in a number of Palestinian communities hemmed in by the serpentine fence to east, north and south while army roadblocks mark Israel's "Green Line" border to the west.

The Jewish state says it is building the 100-metre (330-foot) wide obstacle course of electronic fences, barbed wire and walls to keep out suicide bombers, who have struck repeatedly during a three-year-old Palestinian uprising.

But the barrier has been criticised by U.S. officials for seeming to annex territory where Jewish settlements have spread.

In a speech during his visit to Britain, Bush made headlines by branding the barrier an obstacle to peace.

"Israel should freeze settlement construction...end the daily humiliation of the Palestinian people and not prejudice final negotiations with the placement of walls and fences," he said, referring to a fraying U.S.-backed peace plan.

But Israel fended off the flak, vowing to press on with the barrier, calling it vital for security.

"If Israel can simply brush off its big protector like that, then Bush's message is worthless no matter how tough," said Faris Khandaji, a teacher in Baqa as Sharqiya.

"We can only conclude that Bush's only intention was to display some kind of pseudo-balance on the Israeli-Palestinian conflict to his hosts and the world at large."

Israel says it aims to minimise hardships to the Palestinian population from the barrier, citing 29 "farm gates" slotted into the 150 km (95 miles) built so far.

But residents of Baqa as Sharqiya and other villages say the gates have been opened only briefly at varying times of the day and then shut for extended periods without cause. Israel cites security alerts for the closures.

Only two of Baqa as Sharqiya's 24 schoolteachers live in town. The rest confront the barrier daily and many frequently arrive late for class or not at all, they say.