WASHINGTON, DC: Reports from inside two Syrian chemical weapons facilities offer some chilling new evidence that President Bashar al-Assad’s regime developed special vehicles last year for moving and mixing the weapons — and an unconfirmed allegation that Lebanese allies of the regime, presumably in Hezbollah, may have been trained 11 months ago in the us of these weapons.

A Syrian source provided a detailed account in a telephone conversation over the weekend, drawing on intelligence provided to him by a Syrian defector who worked inside the chemical weapons network. The source was speaking from an Arab country outside Syria where he has taken refuge. The conversation was arranged by the Syrian Support Group, an organization in Washington that speaks for moderate elements of the opposition Free Syrian Army.

This information comes with a caveat: The Syrian sources want to alert the US to dangers there partly in the hope of encouraging greater American involvement with the opposition. For some historical context, readers should recall the Iraqi defector known as “Curveball,” who made allegations about Iraqi chemical weapons a decade ago that bolstered the case for war—but turned out to be fabrications. Seeking corroboration for the Syrian report, I checked it with knowledgeable, independent sources, who confirmed some of the details. With that support, I want to share it with readers.

According to the defector’s account, two senior Syrian officers moved about 100 kilograms of chemical weapons materials from a secret military base in January 2012. The base was in a village called Nasiriyah, about 50 to 60 kilometers northeast of Damascus.

The officers placed the chemicals in a civilian vehicle and were seen driving across a bridge in the direction of the highway toward Lebanon, the Syrian source said. Two days later, he continued, two men with Lebanese accents arrived at the Nasiriyah base and were given training in how to combine and activate the chemicals, as well as the proper safety precautions in handling them.

Rumors about possible movement of Syrian chemical weapons have been spreading recently in the Middle East. But US officials don’t appear to have any evidence that chemical weapons have actually been moved anywhere outside Syria.

The Syrian source also described construction of special trucks, which could transport and mix the weapons, at a workshop in the Dummar suburb northwest of Damascus. This workshop was part of a network of secret research facilities known in Arabic as the “Bohous,” the source said. Construction of these mobile laboratories began in the summer of 2011, a few months after revolutionaries began threatening Assad’s regime.

In the Dummar workshop, the Syrian source said, technicians constructed a mobile lab that could combine and activate so-called “binary” chemical weapons agents. These mobile mixers were constructed inside Mercedes or Volvo trucks that appeared, from the outside, to be similar to refrigerator trucks. Inside were storage tanks, pipes and a motor to drive the mixing machinery, the defector said.

The defector estimated that 10 to 15 of these mobile laboratories had been constructed. An independent source said these numbers were high, but he confirmed that the Syrians do have mobile labs.

Drawing on the defector’s reports, the Syrian opposition quietly gave Lebanese officials a description of the trucks about six week ago, so that they could monitor whether the vehicles were crossing into Lebanon with chemical weapons on board. Since then, none have apparently been seen near the border.

The Nasiriyah facility is near the town of Qalamoon. People who worked at the base spoke often of visits there by Maher al-Assad, the president’s brother, who commands the elite military unit known as the Republican Guard. He is thought to be the military leader of the savage campaign against Syrians rebels, which has led to the deaths of an estimated 40,000 people over the past 20 months.

An independent source confirmed that both the Dummar and Nasiriyah facilities mentioned by the defector are, indeed, part of the Syrian chemical weapons network.

What should we make of these reports? First, the Syrian chemical warfare capability may be even more dangerous than people had thought, because the weapons can be moved to other locations and mixed en route. And, second, there’s a significant risk of proliferation to other groups, such as Hezbollah, which could pose a global terrorist threat.

This new information underlines that the war in Syria contains seeds of a wider and more dangerous conflict. The warning light is flashing: Handle urgently, and with care.

(c) 2012, The Washington Post Writers Group