FBI: Man was not carrying explosives in Pentagon alert

Police in the US blocked off roads around the Pentagon and searched the surrounding area after arresting a man in Arlington National Cemetery overnight.

An FBI spokesperson said the man was carrying a backpack with suspicious items and products.

However, no explosive devices or materials were found.

A car was also searched as part of the operation.

US authorities are on alert for revenge attacks following the killing last month of al-Qaida chief Osama bin Laden in a US raid in Pakistan.