Tehran, Aug 25 (IANS): Crossing the red line on Syria will have "dire consequences" for the US, Iranian Deputy Chief of staff Gen Masoud Jazayeri warned Sunday.

"The US is clear about the Syria red lines and any transgress of Syria red lines will have dire consequences for the US," Xinhua quoted Jazayeri as saying.

He was alluding to recent statements of the US commanders about possible military intervention in Syria over the alleged involvement of the Syrian government in a chemical attack on civilians.

On Aug 21, Syrian opposition claimed that 1,300 people were killed in a government chemical attack on militant strongholds in the Damascus suburbs of Ain Tarma, Zamalka and Jobar. The government has denied the charge.

More than 100,000 people have been killed in Syria since the conflict began in March 2011, according to UN statistics.

Iran is the main ally of the Syrian government in the region and has encouraged the Lebanese Shia Hezbollah group to fight on the side of the government forces against the Syrian rebels.