At least five Palestinians have been killed in an Israeli raid on a refugee camp in the West Bank town of Jenin.
Israel said soldiers recovered weapons and explosive belts
Witnesses said about 10 Israeli tanks - backed by armoured vehicles and jeeps and two combat helicopters - surrounded a house used by Islamic Jihad militants during the raid.
Israeli military sources said an operation was in progress in the camp and that there were heavy exchanges of fire.
The military says six Palestinians have been killed in the raid, while the Palestinian Red Crescent puts the toll at five.
An Israeli military source said that several M-16 and Kalashnikov rifles were recovered following the incident, in addition to explosive belts and Israeli army uniforms, the Reuters news agency reported.
Earlier, Israeli troops shot dead five Palestinians during clashes as they moved into the town of Tamoun, north-east of the city of Nablus.
And on Thursday, near Hebron, two Israelis were accidentally killed by their own army, which mistook them for Palestinian militants.
Palestinian security sources said the five Palestinians killed in Tamoun all belonged to radical militant groups.
Israeli forces entered the town to search for the militants, who they thought were planning an attack, and were fired on by Palestinian gunmen, the Israeli army said.
Two Israelis died when their car was riddled with bullets by friendly forces
An explosive belt was found on the body of one of them, a spokesman added, and the Israeli military said that at least four of the militants were high on their list of fugitives.
Eleven Palestinians were also arrested in Hebron as part of ongoing Israeli operations, the Israeli army said.
BBC correspondent Richard Myron in Jerusalem said that the operations illustrated Israeli military tactics of targeting those it suspects of carrying out operations against Israeli targets.
Palestinian cabinet minister Saeb Erekat condemned the raids as part of a "new massacre", accusing the Israeli army of using possible conflict in Iraq as a pretext to carry out military raids.
"We urge the international community to intervene immediately in order to prevent Israel from continuing to exploit the crisis in Iraq to carry out its aggressive plans in the West Bank and the Gaza Strip," Reuters.
The accidental shooting happened south-east of the city of Hebron as the two armed Israelis, reportedly security guards from a nearby research site, were travelling in a car, the army said.
Bullets riddled the front of the vehicle, which had the word "security" written in Hebrew on both doors and the hood.
Israeli troops were hunting suspected Palestinian militants after receiving intelligence warnings that they were planning an attack, the army said in a statement.
The army expressed regret at the error, calling it an "operational failure" and immediately launched an inquiry into the incident.