Riot squads ring Jerusalem's Old City to curb growing Palestinan protests

The confrontations come in a week in which visiting US vice-president Joe Biden condemned Israel for approving new building, just as Washington was pushing its key Middle East ally to relaunch peace talks with the Palestinians.

Police said a plan to avert a repeat of clashes in which dozens were wounded last Friday had worked.

Four Palestinians were detained on suspicion of throwing stones and two officers were slightly injured in Jerusalem, a police spokesman said.

Israel barred Palestinians from crossing from the West Bank into Israel and Jerusalem, and barred men under 50 from al-Aqsa mosque, the flashpoint holy site in the walled Old City.

As hundreds of youths streamed away from noon prayers at a mosque in the district of Ras al-Amud, witnesses reported men throwing stones at a car carrying Orthodox Jewish children. One smashed a side window, but there were no obvious injuries.

In the blockaded Gaza Strip crowds protested at Israel's policies in Jerusalem. "We will redeem al-Aqsa mosque with our souls and our blood," some chanted.

As demonstrators burned US and Israeli flags, Khalil al-Hayya, a leader of the Hamas movement which rules Gaza, urged Hamas's rival, West Bank-based Palestinian president Mahmoud Abbas, to reverse his decision to engage in "proximity talks" with Israel through US mediators after a hiatus of 15 months.

"These direct and indirect negotiations provide a cover to the Zionist aggression against our people and our lands," Hayya told the crowd. "Our angry people now are calling on the Palestinian negotiator to back off from these negotiations which encourage more settlements and the Judaisation of Jerusalem."

Earlier, the United Nations' humanitarian chief said Israel's blockade of Gaza is not helping its security nor weakening Hamas' hold on the territory.

John Holmes also warned that as bad as the hundreds of tunnels that bypass the blockade are, Gaza would have difficulty surviving if Egypt succeeds in blocking them because they are a conduit for badly needed goods including food and medicine.

Egypt has a fence along Gaza's southern border and is reinforcing the area with underground metal plates to shut down the tunnels.

Mr Holmes again called on Israel to allow the normal entry of goods, and said: "If those tunnels were blocked, however undesirable they may be, and however undesirable the effect they're having on the Gazan society and Gazan economy, the situation without the tunnels would be completely unsustainable.".

The tunnels are also believed to be used for smuggling cash and weapons to Hamas, which refuses to recognise Israel. The Israeli government has repeatedly tried to shut the tunnels down.

Egypt's President Hosni Mubarak has defended the move as necessary for his nation's security following a series of terrorist attacks on nearby tourist resorts.

Mr Holmes said it was "very frustrating" to see that there has been almost no rebuilding in Gaza, as a result of the Israeli blockade, since the three-week conflict that ended in Jan. 2009, leaving 13 Israelis and almost 1,400 Palestinians dead.