Eight people have been hospitalized over a suspicious substance that was found at a building on US Capitol in Washington, DC.

Timothy Wilson, a spokesman for Washington, DC fire department confirmed the report Friday, adding that the substance was found at the Longworth House Office Building, one of the three buildings used by the House of Representatives.

Wilson added that the fire crew evaluated 10 people and took eight to various hospitals in the area. He could not immediately describe the symptoms but said they were minor.

Captain Kimberly Schneider, a spokeswoman for the US Capitol Police, said that there was no immediate information available on what the substance might be.

The substance was found in Suite B-227, the First Call Service Center, according to police.

The building’s cafeteria was closed by police after some of the individuals reportedly said they had felt sick there.

The House Sergeant at Arms office issued a statement, citing exposure to lead as the main reason behind the situation.

No offices were evacuated at the building, which is located just south of the US Capitol, where members of the House of Representatives have offices.

The incident prompted police to briefly close the nearby streets.

Back in October, police closed down the Cannon House, another building on the Capitol Hill upon the discovery of a possibly hazardous "white and powdery" substance.

However, the building was reopened after tests rendered the powder harmless.