The most dangerous regional arm of Al Qaeda may be trying to produce the lethal poison ricin to use in explosives for attacks against the United States, President Barack Obama and American counterterrorism officials are fearing. For over a year, Al Qaeda’s affiliate in Yemen have been making efforts to acquire large quantities of castor beans, which are required to make ricin, MSNBC is reporting.

Intelligence officials are saying they have collected evidence proving Qaeda operatives are trying to move castor beans and processing agents to a hideaway in Shabwa Province. The officials also say the evidence points to efforts to secretly create batches of the poison. After packing the rocin around small explosives, the operatives may try to explode them in contained spaces, like shopping malls and airports.

Ricin is a white, powdery toxin that is so deadly that exposure to even a minuscule amount can kill if it’s inhaled or reaches the bloodstream. However, senior American officials are stating the ricin’s utility as a weapon is limited, because it loses its potency in dry, sunny conditions. It’s also not easily absorbed through the skin, unlike many nerve agents. But the officials are tracking the possibility of a threat closely, given Yemeni affiliate’s proven ability to devise plots.

Written by: Karen Benardello