The Jerusalem-based center said in a press statement that the number includes Arabs and Palestinians.

The center added that there are 38 men still missing. It also said that the remains are held in conditions that do not preserve the dignity of the dead.

According to the center, the Israeli authorities agreed to hand over the remains of Palestinian martyr Mashhour Al-Arouri to his family if they paid 12,000 Israeli shekels ($ 3,200) for carrying out a DNA test.

However, the center said that the test results were not positive. Al-Arouri's family is still demanding that Israeli authorities release their son, who was killed in 1976.

The center said that Israel "is defying basic international laws in punishing the dead."

It stressed that the "detention of the martyrs' remains in the Cemeteries of Numbers without proper burial is a punishment to their families."

"Holding of the martyrs' remains for many years raises doubts and accusations that Israel assassinated them after detention or harvested their organs," the center said.

Meanwhile, the Israeli Beer Sheva District Court extended the remand of the Popular Front for the Liberation of Palestine’s (PFLP) secretary-general in solitary confinement for an additional six months.

A campaign to free Ahmad Sa'adat said in a press statement that the jailed leftist Palestinian leader will serve the term in a solitary confinement in Ishel prison in the southern Israeli city of Be'er Sheva.

It added that the court's judges took the decision after the Israeli prosecution submitted a "secret file" against the PFLP leader.

It added that the decision proves that Israel is a "state governed by the intelligence agencies."

It also said that the "suppressive Israeli measure prevents Sa'adat's family from visiting him."

Sa'adat is serving a 30-year jail term for overseeing the PFLP's military operations, membership in an illegal organization, arms dealing and incitement.

He was charged of being behind the assassination of Israeli Tourism Minister Rehavam Ze'evi in October 2001.

The PFLP had claimed responsibility for the killing, saying it is a response to the assassination of its leader Abu Ali Mustafa by Israeli forces in his Ramallah office in August 2001.

Israel kidnapped Sa'adat from a Palestinian prison in Jericho in 2006. He and other PFLP suspects were being held in the prison under the supervision of American and British wardens, in accordance with a deal reached in 2002.

In an arrangement brokered by the United States that opened the way for Israel to lift a month-long siege of then-Palestinian President Yasser Arafat's compound in Ramallah, the PA had taken the six men into custody.