Government forces in Syria used chemical weapons against rebels near Damascus, an opposition campaigner told Reuters on Monday.
Rebels had surrounded an army base in the town of Adra, on the outskirts of Damascus, when soldiers used rocket launchers to fire the weapons at them, killing two fighters and wounding 23, according to activist Mohammad Doumani. The claim could not immediately be verified by NBC News.
"Doctors are describing the chemical weapon used as phosphorus that hits the nervous system and causes imbalance and loss of consciousness,” Doumani told Reuters from the nearby town of Douma, where the wounded were transported for treatment.
“The two fighters were very close to where the rockets exploded and they died swiftly. The rest are being treated with Atropine," he added.
There was no independent confirmation of the attack, which follows the death of 26 people in a rocket attack near the city of Aleppo last week. The authorities and rebels accused each other of firing a missile carrying chemicals there.
On Tuesday, both the rebels and the government claimed a chemical weapon was used during fierce fighting, with each side blaming the other for the attack.
Reporting from inside Syria is increasingly difficult, and independent confirmation of the use of chemical weapons was impossible to ascertain.
U.N. Secretary-General Ban Ki-moon on Thursday announced that the United Nations will launch an investigation into the allegations.
However, the prospects for a quick conclusion to the probe will depend on cooperation from the warring parties and safety for investigators — problematic conditions in the chaos of the country's civil war, experts say.
Reuters contributed to this report.