Militants appear to have planned their seizure of a Russian school carefully, starting months earlier and sneaking weapons into the building in advance.

Still, some of the raiders may not have known what they were getting into and were appalled to find they were holding children hostage.

Some of the objecting militants were killed by their own comrades, the lawyer for a captured militant told The Associated Press.

Pieces of the picture of how militants took more than 1,000 hostages at the school in Beslan (search) were falling into place, mainly from news reports citing unspecified but presumably official sources.

Officials are saying little publicly — Federal Security Service (search) spokesman Sergei Ignatchenko declined to immediately respond to questions from The Associated Press on Monday.

But the reports portray the raid as a fastidiously prepared operation — in which militants used renovation work as a cover to plant arms and explosives in the school — almost literally under authorities' noses.

School No. 1 in Beslan, which the militants seized Wednesday on the first day of the new school year, is only about 200 yards from the local police department headquarters.

"Why the law-enforcement bodies didn't know and why they allowed a column of fighters to get into the city past all checkpoints — this is something that can be judged only through rumors," the newspaper Novye Izvestia said Monday.

The band of hostage-takers — some reports have said there were over 30 — were demanding independence for Chechnya and were a mix of ethnicities, including Chechens and up to 10 Arabs, according to Russian officials.

After the hostage-taking ended Friday in a frenzy of shooting and explosions, Russian news agencies cited unnamed security sources as saying that the planners of the raid were believed to have scouted at least two schools in Beslan.

"Judging by everything, they felt the better one for their goals was the main building of School No. 1 with its half-basement gymnasium annex, where the floor had to be replaced," the ITAR-Tass news agency quoted a law-enforcement official as saying.

"The bandits were able to bring into the school a large quantity of weapons, ammunition, equipment and explosives, under the guise of planks, cement and other building material, enough to defend the seized place for a long period," the official said.

Regional security service head Valery Andreyev appeared to reluctantly agree.

"The special services are carefully checking the version that the terrorists brought in arms, explosives and ammunition ahead of time," he said, according to the Interfax news agency.

That hypothesis appears to conform with other details of the seizure. The approximately 30 raiders arrived in a single military-style truck — believed to have been hijacked in neighboring Ingushetia (search) — which, jammed with people, would have been too small to carry much equipment.

Hostages also spoke in news accounts of a huge quantity of explosives in the school — not only the suicide belts worn by some of the hostage-takers, but bombs hung from basketball hoops and a 2-foot-square bomb built in the center of the gym.

Such a plan echoes some of the recent years' most brazen terrorist attacks. The Kremlin-backed president of Chechnya, Akhmad Kadyrov (search), was killed in May by a bomb in a stadium in Chechnya's capital that was believed to have been planted during reconstruction work.

The huge bombs brandished by the raiders who seized a Moscow theater in 2002 were believed to have been spirited in while an office in the building was being remodeled.

The Moscow theater standoff ended when Russian forces pumped in a knockout gas that disabled the militants — and inadvertently killed most of the 129 civilian victims. Perhaps learning from that experience, the Beslan hostage-takers brought along two dogs, possibly to detect gas.

Why the militants scouted Beslan at all was not immediately clear. The city of 30,000 could have been seen as large enough to provide a shockingly high number of victims while not large enough to risk a heavy police presence. It also is the location of the region's main airport and is on a railway line.

But amid the careful preparations, the attack's planners may not have considered psychology.

Umar Sikoyev, a lawyer for a captured militant identified as Nur-Pashi Kulayev, said the band's leader did not tell them what their mission was and that after the seizure a fierce argument broke out in the band, with several objecting that taking children hostage was wrong.

The raid's commander shot the dissidents' leader to death and then detonated the suicide belts worn by two women raiders by remote control to establish order in the band, Sikoyev told The Associated Press.

In footage broadcast on state televsion, Kulayev contradicted the statement that he was not told of the mission, saying the group was told they were to take a school in Beslan. He said they were told they were carrying out a task assigned by Chechen rebel warlord Shamil Basayev (search) and separatist former Chechen President Aslan Maskhadov (search).