Updated

The U.S. Department of Energy says the shipment of certain kinds of nuclear waste from Los Alamos National Laboratory to a storage facility in west Texas has been halted.

The agency made the announcement Friday, as investigators continue searching for the cause of a Feb. 14 radiation leak at the federal government's underground repository in southeastern New Mexico.

Department officials say investigators are evaluating the contents of a set of drums that came from Los Alamos. The team is looking at the possibility that a chemical reaction may have occurred within a drum, causing a potential release.

Officials say they're looking at all possible causes, including the waste packages themselves.

Los Alamos is under a tight deadline to get waste off its northern New Mexico campus before wildfire season peaks.