A year after Cpl. Gilad Schalit's abduction on the Gaza border, the Israeli human rights group B'Tselem plans to publish a statement on Monday morning that holding Schalit as a hostage is "a war crime." The group calls for the immediate release of Schalit. "Hamas, which de facto controls the security apparatus in the Gaza Strip, bears the responsibility to act to release Schalit immediately and unconditionally. Until he is released, those holding him must grant him humane treatment and allow representatives of the International Committee of the Red Cross to visit him. The fact that Schalit's right to these visits has been denied constitutes a blatant violation of international law," B'Tselem's statement reads. Several hundred people attended a protest rally in Jerusalem on Sunday marking one year since Schalit was kidnapped by a group linked to Hamas, and almost a year since the abduction of reservists Ehud Goldwasser and Eldad Regev by Hizbullah. Among those at the rally were families of the soldiers and residents of Mitzpeh Hila, Gilad Schalit's home community in Galilee, who drove to Jerusalem in a procession of vehicles. Speakers called on Prime Minister Ehud Olmert to "bring the boys back home" at any cost - including freeing prisoners "with blood on their hands." "The current situation in Gaza is a window of opportunity that we didn't have before to free Gilad in exchange for prisoners," said Noam Schalit, Gilad's father. "At the same time, I call on the Palestinians, Hamas and the families of the prisoners - this is your chance, as well, to free your relatives." "If an entire country, its leaders... the sophisticated systems it has, satellites, drones, can't bring back a soldier from captivity after an entire year, and can't even get firm information about his condition and health, then we should all be worried," Schalit added. Olmert, speaking at the weekly cabinet meeting, said the government was making "supreme efforts" to free Schalit. "We have done, and will continue to do, everything that can be done - there are complicated issues here, moral ones as well - and we won't stop our efforts to bring about the release of Gilad Schalit as soon as possible," Olmert said. Zvi Regev, Eldad's father, urged the government to secure the three soldiers' release "even at a high price - and at any price." "It is possible to bring Gilad, Udi and Eldad home, and immediately," he told the crowd. Ora Pearl Mintz, mother of St.-Sgt. Raz Mintz, who was killed in November 2001 by Palestinian gunmen near the settlement of Ofra, called on Olmert not to rule out a deal with the abductors to release the kidnapped soldiers, even at the price of freeing her son's murderers. "There is no price on my son's life, but there is a price on the lives of Gilad, Ehud and Eldad," she said. Author Meir Shalev joined the general message: "This government does not do what has to be done. This state, whose government... released prisoners for [kidnapped businessman] Elhanan Tenenbaum... and in exchange for bodies [of IDF soldiers Beni Avraham, Avi Avitan and Omar Saoud], is not making a deal," Shalev said to applause from rally attendants. The only opposing voice at the rally was Rami Igra, former head of the Mossad's Captured and Missing Department. Igra said that in his experience, "people who work on freeing the soldiers are eager to bring the soldiers back home. There is no more important mission for them and [the kidnapped] are on their minds 24 hours a day." "Nonetheless, in the Schalit case, there is really no one to negotiate with. The other side keeps changing its demands constantly. I call on this house [the Knesset] to transfer this tragedy from Mitzpeh Hila [Schalit's family residency] to the Gaza Strip. Take off your gloves and create unbearable conditions in Gaza that will make them reconsider dealing with us," Igra continued. "A man's life has a price and it is not infinite. The IDF's ethical code says a man will do all that is in his power to bring back his friends from the battlefield, but within reason. That means that several other soldiers shouldn't pay with their lives in order to bring back one soldier," Igra later told The Jerusalem Post. "We cannot free prisoners with blood on their hands and take the risk that more abductions could happen as a result" He went on: "Israel faces a Talibanistic regime in Gaza whose codes of morality are completely different than ours. If Israel wants to handle these people, the rules of the game have to be changed." The families of the kidnapped soldiers did not share Igra's sentiments. In response, Schalit's father said: "Our sons didn't go to Lebanon and Gaza of their own free will. If the prime minister doesn't know what he should do, he should pass his responsibilities to someone else, who can." AP contributed to this report.