WASHINGTON(National times)- Seven people were briefly hospitalized after a suspicious package containing a white powder was opened at the military base near the US capital that is home to Air Force One, the presidential jet, US media reported. The CNN television network said initial tests of the unknown substance by a HAZMAT team found it not to be hazardous but an investigation was ongoing. The individuals at Joint Base Andrews who were taken to hospital on Thursday were subsequently released, CNN said. Fox News said some of them had reported experiencing headaches. CNN, citing sources familiar with the investigation, said the package also contained what was described as “political propaganda.” “Joint Base Andrews responded to an incident here today after an individual opened a suspicious package,” the base said in a statement to US media. “As a precaution, the building and connecting building were evacuated. “Joint Base Andrews first responders were dispatched to the scene, determined there were no immediate threats, and have turned the scene over to Office of Special Investigations,” the statement said. Joint Base Andrews in Maryland is a short drive from Washington and is used by senior US government officials. President Donald Trump landed at the facility as recently as Wednesday on an Air Force One flight returning him from a business forum in Florida. CNN said the package was opened in a building that houses the Air National Guard Readiness Center on the sprawling base.