Two Palestinians have been shot dead by Israeli soldiers near the West Bank town of Tulkarm, Palestinian security officials have said.
Witnesses said the soldiers opened fire on unarmed protesters who were throwing stones at their jeep.
An Israeli army spokesman said the Palestinians were shot and killed only after the vehicle had come under fire.
In a separate incident, a Palestinian police officer was shot and wounded as he tried to settle a row in Tulkarm.
Palestinian gunmen fired on police after they were called to the scene of the argument in a coffee shop.
The shooting was the latest incidence of lawlessness in towns and cities handed back to Palestinian police control by Israel earlier this year.
US President George W Bush urged Palestinian leader Mahmoud Abbas to crack down on "armed gangs" in Palestinian territories during talks in Washington on Thursday.
Tensions have increased in the West Bank since the killing of three Jewish settlers in a drive-by attack at a hitchhiking post near the Gush Etzion settlement on Sunday.
In response, Israel re-imposed a series of restrictions on Palestinians travelling through the West Bank.
A Palestinian was shot dead by Israeli troops on Thursday near Bethlehem after he threw a firebomb at their vehicle, Israeli military sources said.