Baltimore officials evacuated four blocks of buildings and closed downtown roads after a van filled with potentially stolen gasoline was discovered in the parking garage of a large office building.

Baltimore police initially said they found a van filled with "around 1,000 gallons" of gasoline Monday morning, evacuated several buildings near the Inner Harbor, and advised people to stay away from the area.

A Maryland Department of the Environment spokesman said later 80 gallons of diesel fuel had been off-loaded from the van.

A large emergency response, including fire officials and the Bureau of Alcohol, Tobacco, Firearms and Explosives and the U.S, Customs and Border Patrol assisted in an investigation spanning several hours.

By Monday afternoon, Mayor Jack Young's office said no bombs were detected during the investigation.

"We are currently in the process of conducting precautionary sweeps in an effort to ensure public safety," a statement from his office said. "These sweeps are expected to take several hours."

Then, late Monday afternoon, police said they discovered a machine used for stealing diesel fuel and two bins full of possibly-stolen diesel fuel inside the van, rather than the 1,000 gallons of gasoline police reported in an earlier news conference and gave  city council members.

The precautionary sweeps continued after the police's update.

In a news conference earlier Monday afternoon, police said they responded to the "possibility of a vehicle leaking gas" at a parking garage at 100 E. Pratt St. Police found the van upon arrival and evacuated the 28-story building, which houses the offices of T. Rowe Price, Merrill Lynch and Pricewaterhousecoopers. They also evacuated the Gallery shopping mall, the Renaissance Baltimore Harborplace and Brookshire Suites hotel.

Col. Sheree Briscoe, chief of detectives, said the city police and fire departments evacuated the area in a four block radius out of public safety concern.

“At this point we just want to ensure that all of our community is safe,” Briscoe said.

The evacuated radius ran from East Baltimore Street to the north, Conway Street to the south, South Charles Street to the west and Commerce Street to the east.

"Those who have a vehicle parked in the evacuated area, we ask that you please find alternative transportation home," Mayor Young's office said. "We will send an update when the area is cleared and you are able to pick up your vehicle."

This post has been updated.