The government provided details Sunday of new intelligence it had obtained that led to the increased threat level against financial institutions, including several specific buildings.

A senior intelligence official described the details only on condition of anonymity. He said it was the most extraordinary detail he had seen in 24 years of intelligence work.

— The flow of pedestrians outside one building — 14 people per minute midweek on each side of the sidewalks, or 28 per minute.

— Information that some explosive materials may not be hot enough to melt the steel underpinnings of a building, and a reference to what materials might heat to 2,700 degrees.

— Suggestions for building reconnaissance, such as a window table at a nearby coffee shop.

— Details about specific security checkpoints inside buildings, including a tidbit that people turned left after passing one checkpoint.

— Places to make contact with building employees.

—Construction of some buildings that might prevent their collapse.

— Locations of police stations, fire departments, schools and hospitals in the vicinity of the targets.

— Changes in day-to-day security, including lessened security on Sundays and days when elevators don't operate.