Israeli troops handing out eviction notices to Jewish settlers in the Gaza Strip have encountered defiant, but non-violent, resistance.
Settlers formed human chains to try to block the troops at Neve Dekalim
At Neve Dekalim, the largest outpost, settlers, joined by Jewish hardliners from elsewhere, blocked the main gates, trying to keep the troops out.
About 9,000 people now have two days to leave all Gaza settlements and some in the West Bank or be forcibly removed.
More than 40,000 Israeli soldiers and police are part of the operation.
This is the first time that Israel has agreed to dismantle settlements built on Palestinian land seized in the Six-Day War in 1967.
Palestinian leader Mahmoud Abbas hailed the move as "historic" but said Israel should also pull out of the West Bank.
Hundreds of Palestinians marched through Gaza City to mark the start of the withdrawal and others headed for mosques to give thanks in a mass prayer meeting called by the militant group, Hamas.
Those living in Gaza's 21 Jewish settlements, and those in four of the West Bank's 120 settlements, have until midnight on Tuesday to leave.
Settlers who ignore the final deadline are to be forcibly removed and could lose up to a third of their compensation.
Tears from both sides
About half of Gaza's 8,500 settlers have already left. But those remaining have been joined by about 5,000 hardliners from Israel and the West Bank.
At Neve Dekalim the unarmed soldiers delivering the notices were confronted by protesters calling on them to disobey their orders.
The BBC's Richard Miron at Neve Dekalim says this is a highly emotional moment for both sides. Many protesters were in tears, along with a few soldiers.
Settlers spoke of feeling betrayed by the Israeli government's decision to evict them.
"I think that all this process is immoral, all this plan is just a disaster for us and when my government said it would find a solution for every settler, we find it a lie, because we are more than 600 families with no solution," Debbie Rosen, one of the residents at Neve Dekalim, told the BBC.
"We don't know where to go. We don't know where our kids are going to school and it is two weeks before the 1 September and there's nothing prepared for us," she added.
In an apparent attempt to avoid violence, the army has said it will not deliver notices to settlements where residents have threatened resistance. Instead the notices are being sent by post.
The settlements have been sealed off to prevent any more protesters joining those resisting eviction.
The Israeli cabinet on Monday gave final approval for the evacuation of the Gush Katif group of settlements - which includes Neve Dekalim.
There were scuffles with soldiers at several sites early on Monday. Some settlers burnt their belongings.
"I don't want to leave anything for the Palestinians, anything I own they could enjoy," Yaakov Mazal-Tari, a farmer at Rafiah Yam, told Reuters news agency.
Although the pullout as a whole has already been approved by the cabinet and parliament, ministers agreed last year to hold a final vote on the evacuation of each settlement or group of settlements.
Last week they gave approval for the three isolated Gaza settlements of Kfar Darom, Morag and Netzarim.
In an interview with the BBC Mahmoud Abbas said that he believed the pullout would help to promote security and stability in the region.
"We see this as a historical moment, as Israel is leaving the settlements for the first time since the beginning of the Arab-Israeli conflict."
Some 7,500 Palestinian security forces have been deployed on the outskirts of the settlements themselves.
Their role is to forestall militant attacks on settlers, and prevent attempts by Palestinians to rush into the settlements.