Israel’s Channel 10 News cites a report from the opposition to Syrian President Bashar Assad that the Syrian army has launched a surface-to-surface missile in a suburb of the capital Damascus, killing more than 100.

The reliability of the report not yet clear, according to Channel 10, and it is not known what type of chemical was used.

According to the report, the Syrian army is bombing the towns of Tamara and Zamalka, on the outskirts of Damascus. The rebels are reporting dozens of injuries. It was also reported that the army has shot down a rebel helicopter.

Several Arab news channel have carried this report. The alleged attack took place while a UN mission with some 20 inspectors is in Damascus to investigate earlier reports of chemical weapons use.

The inspectors are expecting to visit three sites, most notably Khan al-Assal near Aleppo. According to the UN, 13 reports of chemical weapon attacks have been received to date – not including today’s report.

UN chief Ban Ki-moon said the investigators intend to collect samples, conduct interviews with witnesses, victims, and attending medical personnel, and conduct autopsies.

Meanwhile, according to Reuters, the Syrian army has attacked rebel positions in the eastern city of Deir al-Zor on Tuesday, countering a rebel advance that threatened to take the whole city. Deir al-Zor, on the banks of the Euphrates, 270 miles northeast of Damascus, is the capital of an oil-rich region bordering Iraq.