Pittsburgh police this afternoon shut down several Downtown streets for more than an hour because of a suspicious package discovered near the Boulevard of the Allies and Grant Street.

The streets were reopened after the device was detonated by the police bomb squad at about 4:40 p.m. The incident snarled traffic throughout Downtown.

The Grant Street exit of the Parkway East was closed, as was the inbound Liberty Bridge exit to the Boulevard of the Allies.

Grant Street was closed from Forbes Avenue to the Parkway East entrance. The Boulevard of the Allies was blocked at Smithfield Street. Other affected streets were Ross Street, Court Place, First Avenue and Third Avenue.

Several Port Authority bus routes were detoured.

Police described the package as a black box about 3 feet by 1 1/2 feet by 2 feet covered with a piece of orange mesh. After blowing it up, they said it contained a large number of "personal items" including papers and letters.