An Al Qaeda affiliate in Algeria closed a base earlier this month after an experiment with unconventional weapons went awry, a senior U.S. intelligence official said Monday.
The official, who spoke on the condition he not be named because of the sensitive nature of the issue, said he could not confirm press reports that the accident killed at least 40 Al Qaeda operatives, but he said the mishap led the militant group to shut down a base in the mountains of Tizi Ouzou province in eastern Algeria.
He said authorities in the first week of January intercepted an urgent communication between the leadership of Al Qaeda in the Land of the Maghreb (AQIM) and Al Qaeda's leadership in the tribal region of Pakistan on the border with Afghanistan. The communication suggested that an area sealed to prevent leakage of a biological or chemical substance had been breached, according to the official.
"We don't know if this is biological or chemical," the official said.
The story was first reported by the British tabloid the Sun, which said the Al Qaeda operatives died after being infected with a strain of bubonic plague, the disease that killed a third of Europe's population in the 14th century. But the intelligence official dismissed that claim.