War crimes tribunal spokeswoman Nerma Jelacic said tribunal staff were handing Mladic his indictment and explaining the rules and procedures to him before placing him in an isolation cell for the night. She said isolation is standard for new arrivals at the prison.
Mladic also was being given a list of defense lawyers who could help him through the initial proceedings of the war crimes court. He would be examined by a doctor and receive any treatment he may need before the end of the day, Jelacic said.
It was unclear when Mladic will appear in court for an initial appearance, but it must be within a few days. The chief prosecutor and top tribunal official scheduled a news conference for noon (1000GMT) Wednesday.
When he appears in court Mladic will be asked to formally confirm his identity and enter a plea to each of the charges against him. He also will be asked whether he has any complaints about the arrangements in the prison.
Like his old ally and political boss Radovan Karadzic three years ago, Mladic may decline to plead to the charges at his first appearance, instead opting to delay a formal response by up to a month. Karadzic's trial, which resumed Tuesday after a two-month recess, is still in its early stages.
Mladic has said he does not recognize the authority of the U.N. tribunal.
Mladic was extradited from Belgrade on a Serbian government executive jet earlier Tuesday, following his capture last Thursday at the home of a relative in a Serbian village. Judges in Belgrade rejected his appeal to delay his transfer on grounds of ill health, and the Serbian justice minister authorized his handover to U.N. officials in The Hague.
After the two hour flight, he was driven to the prison from Rotterdam airport in a convoy of black vehicles with flashing blue lights and an escort of two police helicopters.
In Belgrade, Justice Minister Snezana Malovic said the handover marked the fulfillment of Serbia's "international and moral obligation."
"Mladic is charged with the most serious crimes against humanity and the most serious violations of international humanitarian law," she said.
Mladic faces charges of genocide and other war crimes for atrocities committed by Serb troops under his command during Bosnia's 1992-95 war, including the notorious Srebrenica massacre in July of 1995 and the 44-month siege of the capital, Sarajevo.
Mladic's extradition brought a satisfied response from war victims.
"This means a lot to the victims of genocide," said Munira Subasic, head of the Sarajevo-based Association of Srebrenica Massacre Survivors.
"Mladic has left and we believe that the evil will speak out of him and that he will tell the truth," Subasic said.
In Bosnia, Serb nationalists staged demonstrations in support of Mladic, some carrying banners that said: "The eagle is gone but the nest remains."
Mladic attorney Milos Saljic visited him in his jail cell in the early afternoon and said the former general was crying and very emotional during what he called a farewell visit by his wife and sister. They brought him a big suitcase with clothing he will need in The Hague, Saljic said.
Mladic had spent 16 years on the run. When he was caught leaving his relative's house for an early morning walk he was looking worn, disheveled and much older than his popular wartime image. He was said to have suffered at least two strokes.
Earlier Tuesday, Mladic was briefly released from his jail cell, traveling in a secret high-security armored convoy to a suburban cemetery where he visited the grave of his daughter.
At the black marble grave, Mladic left a burning candle and a small white bouquet of flowers with a red rose in the middle.
"We didn't announce his visit to the grave because it is his private thing and because it represented a security risk," deputy war crimes prosecutor Bruno Vekaric said. "The whole operation lasted for exactly 22 minutes and passed without a glitch. He was at the grave for a few minutes. I've been told that he reacted emotionally."
Mladic had repeatedly demanded that he be allowed to visit the grave, a memorial he had avoided for years as he tried to remain underground.
"We had cameras there and 24-hour surveillance, so he could absolutely not show up there," chief Serbian war crimes prosecutor Vladimir Vukcevic told The Associated Press.
Mladic's 23-year-old daughter Ana, a medical student, committed suicide in 1994 with her father's pistol. She reportedly didn't leave a suicide note, but media at the time said she ended her life at Mladic's Belgrade family house because of depression caused by her father's role in the war.
Mladic has rejected the official investigation into her case and claimed she was killed by his wartime enemies, saying the pistol was found in her left hand, although she was right-handed.
Kadira Gabeljic, whose husband and two sons were killed in the Srebrenica slaughter, reacted with disbelief and anger at Mladic's visit to his daughter's grave, saying she almost fainted at the news.
So far, she said, forensic experts have managed to exhume only part of the remains of her sons, Mesud and Meho, who were 16 and 21 when killed.
"He was allowed to do it, and I am still searching for my children for the past 16 years, ever since Srebrenica happened," she said.
"My husband had been found, but what about my children?" she said. "I will wait for years. I might even die before their complete remains are found."
Serb nationalists in Serbia and parts of Bosnia still consider Mladic a hero — the general who against all odds tried to defend ethnic Serbs in the Bosnian conflict. In the Bosnian city of Banja Luka, thousands of supporters protested his arrest Tuesday, in the biggest demonstration so far in the country.
Demonstrators chanted Mladic's name, and carried his picture alongside those of Russian Prime Minister Vladimir Putin and President Dmitry Medvedev, whom they consider their biggest allies.