Israeli police said one of their officers had stopped a Palestinian youth in Jerusalem on Saturday who they said was acting suspiciously. He then pulled a knife and tried to stab them. Officers shot and killed the teenager.

Earlier in the West Bank city of Hebron, Israel's military said an Israeli pedestrian shot and killed a Palestinian who tried to stab him.

The area, where a few hundred Jewish settlers live in close proximity to tens of thousands of Palestinians, is a regular scene of violence.

A Palestinian eyewitness disputed the police account of what happened, saying that the shooting took place when Jewish settlers attacked an unarmed Palestinian man.

In a third incident, a Palestinian woman stabbed a female officer at a border police base in Hebron before the assailant was shot dead.

The latest shootings brings to 40 the number of Palestinians killed over the past two weeks amid rising tensions. Seven Israelis have died in random attacks by Palestinian youths.

A month-long outbreak of violence has been sparked by rumors that Israel was planning to take over Jerusalem's al-Aqsa mosque compound, which is both a Jewish and Islamic holy site.

Israel says there is no major change to its policy on the area, although Palestinians were restricted from entry around a recent Jewish religious holiday. The fact that an increasing number of Jewish visitors have been visiting the site has angered many Palestinians.

Palestinian President Abbas warns of new intifada riskFears are rising of a third intifada# - a Palestinian uprising against what they claim is Israeli oppression.

Israel has deployed soldiers and erected concrete barriers in affected areas and many Israelis now carry weapons to protect themselves.

Washington and the United Nations have appealed for calm.

mm/rc (AFP, AP, dpa, Reuters)