At least 11 people have fallen ill at a military base in the US state of Virginia after opening a suspicious letter, officials say.

The letter arrived at the base at Joint Base Fort Myer-Henderson Hall in Arlington earlier this and was opened in one of the administrative buildings, according to the Arlington County Fire Department.

Specialist Nicholas Hodges told CNN that three of those affected by the letter exhibited symptoms of a burning sensation on their hands and face and were taken to hospital for further investigations.

Another person suffered bleeding from his nose.

Apparently, the letter had passed all security checks and was assumed to be safe. The US Federal Bureau of Investigation (FBI) has taken the envelope to its lab in Quantico for analysis.

Authorities at the base ordered the entire building to be evacuated so that HAZMAT teams could determine and clear the contamination.

“Personnel in the affected building took immediate preventative measures by evacuating the building,” Major Brian Block, a US Marine Corps spokesperson, said.

“Base officials and are coordinating with local HAZMAT teams and FBI. Several Marines are receiving medical care as a result of this incident. No additional details are available at this time as the investigation is ongoing,” Block added.

Law enforcement officials said the letter contained derogatory and at time unintelligible language and was addressed to a senior commander at the base, raising the suspicion that the sender was in some ways connected to the military facility.

The FBI and the Naval Criminal Investigative Service, the US Navy’s primary law enforcement agency, were expected to jointly conduct the investigations.

Source: Presstv