Israel reopened a sprawling desert detention camp this week to hold some of the thousands of Palestinians it has rounded up during its 19-day West Bank sweep, an Israeli military official said Tuesday.

The confirmation came after Associated Press reporters saw resumed activity at the Ketziot camp in the southern Negev Desert. Spotlights beamed down on the site and soldiers stood in guard towers. Civilian and military trucks entered and left, and bright new Israeli flags and military police corps banners hung limply in the baking desert air.

The Ketziot camp held thousands of Palestinians during the first Palestinian uprising, from 1987-93. At the time, prisoners were held 26 to a tent, exposed to searing heat in the summer and bone-chilling cold in the winter. It was closed in 1996.

The army declined to comment on the camp's reopening.

The Palestinian security chief in the West bank, Jibril Rajoub, said reopening the prison would only increase Palestinians' desire for freedom from Israel's control. "The Israelis will discover that they are wrong in their belief that opening this prison ... will break the determination and the unity of the Palestinian people," he said.

In its current offensive, Israel has detained 4,258 Palestinians, including suspected leaders of the Palestinian uprising, the army said.

The army said 387 of the thousands detained this month were previously known terror suspects. Suspicions against others emerged during interrogation and altogether about 1,200 men would be kept in custody, Israeli security sources said. The army has started releasing the others, said the Israel military official who confirmed the camp's reopening, speaking on condition of anonymity.

The first 310 Palestinians were transferred to Ketziot from a prison in northern Israel this week, said Lior Yavne, a spokesman for the Israeli human rights group B'tselem, citing army officials.

The latest top Palestinian to be detained was Marwan Barghouti, the top-ranking grass-roots activist in Yasser Arafat's Fatah movement. Barghouti was taken from his hide-out in the town of Ramallah on Monday.

Israel accuses Barghouti of commanding the Al Aqsa Martyrs' Brigade militia, which is linked to Fatah and has carried out scores of shooting and bombing attacks on Israelis.

Barghouti has never acknowledged he was the militia's leader, though he has said he considered Israeli soldiers and settlers in the West Bank and Gaza Strip legitimate targets for attack. At the same time, Barghouti advocated the establishment of a Palestinian state alongside Israel, not instead of it.

Barghouti was being interrogated Tuesday at a Jerusalem police compound.

Other high-profile detainees included Nasser Awais, a regional leader of the Al Aqsa militia; Thabet Mardawi, an Islamic Jihad leader in the Jenin refugee camp; and Bilal Barghouti of the Islamic militant Hamas group.

Bilal Barghouti, a member of the same extended clan as Marwan Barghouti, is accused by Israel of involvement in two deadly suicide bombings, a June attack on a Tel Aviv disco and a blast outside a Jerusalem pizza restaurant in August.

Security sources said leading suspects were sent to a prison in central Israel, while most other detainees were being held at the army's Ofer camp near Ramallah and several hundred had been transferred to Ketziot.

An Israeli human rights official said she expected most of those would be given open-ended prison time without trial, a policy known as "administrative detention" that has raised protests by human rights groups in the past.

"Some have already been served administrative detention orders," said Hannah Friedman, director of the Public Committee Against Torture in Israel. "Most of the rest will probably receive them too."

A Red Cross spokesman said the organization had asked to visit the prison camps but was still waiting for its requests to be expedited.

Ketziot is known to Palestinians as "Ansar III" after the grim Ansar prison run by Israel during its military occupation of south Lebanon. An Israeli prison in the Gaza Strip was known as "Ansar II."

The desert camp was first used to detain Palestinians shortly after the December 1987 outbreak of the previous uprising. During the first five years of that conflict Israel jailed about 14,000 Palestinians without trial, most of them held at Ketziot, according to B'tselem.