Palestinian knife attacks against Israeli police left two assailants shot dead and three officers wounded on Monday as a new surge in violence raised concerns ahead of Jewish holidays.

There have been eight similar incidents since Friday, coming after Palestinians wrapped up the Muslim celebration of Eid al-Adha last week and as Israel tightened security ahead of major Jewish holidays in October.

The upsurge has shattered several weeks of relative calm.

In Monday's first attack, a Palestinian stabbed two police officers in annexed east Jerusalem before being shot, Israeli authorities said.

A 38-year-old policewoman was in serious condition in intensive care with a stab wound to her neck, while a policeman in his mid-40s needed treatment for moderate stab wounds.

The Palestinian attacker was in serious condition after being shot in the head and limbs at the scene, near the walled Old City's Herod's Gate.

He was identified as Ayman Hassan Al-Kurd, 20, from Ras al-Amud in east Jerusalem.

Surveillance video distributed by police showed the attacker approach the officers from behind before forcefully stabbing them.

Palestinian shops along the same street were ordered closed by police after the attack, shopowners said.

Police spokeswoman Luba Samri said the closures were ordered for officers to search the area, but some shopowners said it seemed like punishment for the stabbing.

"Police told us: 'Either you close or we'll close your shops by force'," fruit and vegetable merchant Samer al-Meswali, 38, told AFP.

- 'Assailant subdued' -

Jerusalem police chief Yoram Halevy said locals should realise they have a stake in events.

"It cannot be that there is an incident like this and life goes on as if nothing happened," he told Israeli Channel Two television.

The US Consulate General in Jerusalem warned all US government employees and their families to avoid the Old City until further notice.

A few hours after the Jerusalem attack, there was fresh violence in Hebron in the occupied West Bank.

Two Palestinians, aged 21 and 17, tried to stab Israeli border police near a flashpoint holy site before being shot, police said.

One of the attackers was killed on the spot while the other later died from his wounds.

One officer was "very lightly wounded in his hand", police said.

After nightfall, a Palestinian tried to stab a soldier but he "subdued the assailant without the use of fire," an army statement said.

While the assailants are believed to have acted on their own, Hamas spokesman Abdel Latif Qanoua on Monday said the Islamist movement that runs Gaza welcomed the attacks.

He called them "a natural response to the crimes of the Israeli occupation against our people".

On the eve of Monday's attacks, the Palestinian foreign ministry condemned what it said were increased Israeli security measures in Hebron, Jerusalem and elsewhere, including new checkpoints and closing off villages.

An Israeli security official, on condition of anonymity, said tensions may be increasing because of Palestinian "online incitement" against Jewish visits to Jerusalem's Old City and its Al-Aqsa mosque compound.

- Tension over holy site

The compound is the third holiest site for Muslims and the most sacred for Jews, who refer to it as the Temple Mount.

The Jewish holidays see an increase in Jewish visitors to the site.

UN Mideast envoy Nickolay Mladenov urged both sides "to take measures to preserve calm and avoid escalation, especially during the upcoming" holidays.

On Sunday, Prime Minister Benjamin Netanyahu extended his nearly year-long order barring members of parliament and ministers from the volatile site.

Clashes erupted at the Al-Aqsa compound last year during the Jewish holidays amid Muslim fears that Israel was planning to change the rules governing the site, claims Netanyahu vehemently denied.

Jews are allowed to visit but not pray there to avoid stoking tensions.

The site is central to the Israeli-Palestinian conflict, with Palestinians fearing that Israel seeks to assert further control over it.

Far-right members of Netanyahu's coalition have called for Jewish prayer rights at the compound, while hardline groups favour construction of a third Jewish temple there.

Since October, 229 Palestinians, 34 Israelis, two Americans, one Jordanian, an Eritrean and a Sudanese have been killed in ongoing violence, according to an AFP count.

Israel says most of the Palestinians killed were carrying out knife, gun or car-ramming attacks. Others were shot dead during protests and clashes.

Many analysts say Palestinian frustration with the Israeli occupation and settlement-building in the West Bank, the complete lack of progress in peace efforts and their own fractured leadership have helped feed the unrest.

Source: AFP