Hundreds of illegal African immigrants began a hunger strike on Monday after Israeli police forcibly broke up a sit-in they were staging along the Egyptian border.
Around 1,000 infiltrators, mostly from Eritrea and Sudan, had marched Friday to the border and set up a makeshift camp to protest against their "inhuman and unlimited" detention at Holot facility.
Israel opened Holot detention camp in the southern Negev desert last year as part of a crackdown on illegal immigrants, with the facility open by day but locked down at night.
The demonstrators have said Holot is akin to prison and have also slammed what they said was Israel's failure to process their asylum requests.
They are calling on the UN refugee agency (UNHCR) to intervene to allow them to immigrate to a third country.
But on Sunday evening, police and immigration officials "violently" broke up the border encampment and took the demonstrators to Saharonim, another detention camp for African immigrants, the demonstrators said in a statement.
"We have been taken to Saharonim prison. Some of us have injuries including to the face and limbs. In protest of this violence, and our ongoing imprisonment we have now started a hunger strike," it said.
"We call on UNHCR to find an urgent solution for this situation and to protect our rights as people who have come to Israel to seek asylum and shelter."
Sabine Hadad, spokeswoman for the Israeli immigration authority confirmed that 779 people had been evacuated during the arrest operation.
"There were clashes with a small minority of demonstrators. Five of them and five police were very lightly injured," she told AFP.
"Each one will be brought before a committee to explain why they violated the rules," she said, indicating the inmates are required to sign in twice during the day, and to spend the night in the facility.
"They could face up to three months imprisonment for this offence," she said.
Under legislation passed by parliament in December 2013, Israel can detain illegal immigrants for up to a year. The law was the latest in a series of measures aimed at cracking down on the numbers of illegal infiltrators. Illegal immigrants from Eritrea and Sudan have been blamed for a massive crime wave in southern Tel Aviv, where most of them are concentrated. Most are economic migrants, as opposed to asylum seekers, and Israeli officials have said unchecked illegal immigration would pose a threat to the tiny state's Jewish character.
Last year, Israel launched a crackdown on the roughly 60,000 illegal African immigrants who live in the country, rounding up and deporting 3,920 by the end of the year, and building a hi-tech fence along the border with Egypt, which brought the influx of illegals to a halt.
The UN says there are some 53,000 refugees and asylum-seekers in Israel, most of whom entered via the desert border with Egypt.
Of that number, some 36,000 come from Eritrea where the regime has been repeatedly accused of widespread human rights abuses. Another 14,000 are from conflict-torn Sudan.