Woman suspected of sending letter containing poison to US President Donald Trump arrested

A woman who is suspected of sending the package containing the deadly poison ricin to US President Donald Trump was arrested after she attempted to enter the United States from Canada through the border, a federal law enforcement official said.

The accused was arrested by US authorities and carrying a gun, the official was quoted by CNN as saying. She is expected to face charges.

A person familiar with the probe told CNN that the package was mailed from St. Hubert, Quebec and contained a granular substance with similar physical characteristics to ground castor beans.

The arrest was confirmed by a spokeswoman from the FBI Washington Field Office and the investigation is currently underway.

Authorities are probing additional similar packages mailed to addresses in Texas that may be connected to the same sender in Canada, according to a US law enforcement official.

"We are aware of the concerning reports of packages containing ricin directed toward US federal government sites," Mary-Liz Power, chief spokeswoman for Canada`s Minister of Public Safety Bill Blair, told CNN on Saturday.

"Canadian law enforcement is working closely with their US counterparts. As this is an active investigation we cannot comment further," she had said.

Law enforcement officials intercepted the suspicious package containing the poison before it could reach the White House. Two tests were conducted to confirm the presence of ricin, CNN reported on Saturday citing two law enforcement officials.

All letters for the White House are sorted and checked at an offsite facility before reaching the White House.

Ricin is a highly toxic substance extracted from castor beans that have been used in terror attacks. It can be used in the form of powder, mist, pellet or acid. If one ingests the poison, it causes vomiting and internal bleeding of the stomach and intestines, failure of the liver, spleen and kidneys and subsequent death by collapse of the circulatory system.