U.S. Customs and Border Protection confirming to Buffalo media, a woman suspected of sending a letter containing the poison ricin to President Donald Trump was arrested at the Peace Bridge as she tried to enter the U.S. from Canada.
CNN was the first to report the arrest quoting a law enforcement official who says the woman was carrying a gun.
The RCMP say the envelope was sent from Canada.
It was intercepted before it reached the White House.
CNN says authorities are investigating additional packages mailed to addressed in Texas that may be connected to the same sender in Canada.
A spokeswoman for federal Public Safety Minister Bill Blair telling the news agency Saturday "We are aware of the concerning reports of packages containing ricin directed toward US federal government sites. Canadian law enforcement is working closely with their US counterparts. As this is an active investigation we cannot comment further."