By Steve Weizman
Deadly Israeli-Palestinian violence looks as if it might escalate after a Jewish holy site was torched in the West Bank.
The overnight arson attack on Joseph's Tomb in Nablus came as Palestinians called for a "Friday of revolution" against Israel.
In clashes along the border with the Gaza Strip, Israeli fire killed two Palestinians and wounded 98.
Another Palestinian died in clashes in Beit Furik near Nablus, while protests also broke out in Bethlehem and Hebron.
And outside a Jewish settlement in the West Bank, a Palestinian disguised as a news photographer stabbed and wounded a soldier before being shot dead.
Seven Israelis have been killed and dozens wounded in the violence so far, while 37 Palestinians have died and hundreds more been wounded in clashes.
In the Palestinian uprisings of 1987-1993 and 2000-2005, thousands were killed and many more wounded in near daily violence.
Israeli security forces have deployed massively in Jerusalem after two weeks of Palestinian attacks in the city and across Israel.
Palestinian president Mahmud Abbas, under pressure over recent comments that some have labelled incitement, quickly condemned the fire at Joseph's Tomb.
Video showed what looked like an extensive blaze, and the Israeli army called it "a despicable act" of desecration.
There were warnings that the fire could worsen the unrest.
"Burning Joseph's Tomb is a dangerous attempt to exacerbate an already tense environment," Nickolay Mladenov, UN special coordinator for the Middle East peace process, said on Twitter.
US President Barack Obama, speaking at a news conference with visiting South Korean President Park Geun-Hye, said "we are very concerned about the outbreak of violence.
"We also believe that it's important for both Prime Minister (Benjamin) Netanyahu and Israeli elected officials, and President Abbas and other people in positions of power, to try to tamp down rhetoric that may feed violence or anger or misunderstanding," Obama said.
"Over time, the only way that Israel is going to be truly secure, and the only way the Palestinians will be able to meet the aspirations of their people, is if they are two states living side by side in peace and security."
But right now, "everybody needs to focus on making sure that innocent people aren't being killed."
On Thursday, Netanyahu reiterated his willingness to meet Abbas, while accusing him of inciting and encouraging violence.
"It's time that president Abbas stops not only justifying it, but also calling for it," Netanyahu told reporters.
Abbas has called for peaceful protests, but had not explicitly condemned any attacks in the recent wave of unrest until Friday's statement on Joseph's Tomb.
He said the arson "offends our culture and our religion and our morals", and that the damage would be repaired.
Many Jews believe the site to be the final resting place of the biblical patriarch Joseph, while Muslims believe an Islamic cleric, Sheikh Yussef (Joseph) Dawiqat was buried there two centuries ago.
The shrine is under Palestinian control and off-limits to Israelis except on escorted trips organised by the army.