State-run SANA quoted Fyodor Lukyanov, the editor-in-chief of the journal Russia in Global Affairs, as warning that "allegations of the Syrian government using chemical weapons could be excuses for foreign military intervention in Syria."

It added, "In a statement to journalists on Tuesday, Lukyanov said that the reports on chemical weapons in Syria could be exploited to undermine the authorities and motivate foreign forces, stressing that there's no proof that chemical weapons have been used and that these reports seem to be another round of the media war against Syria."

U.S. President Barack Obama has previously warned that any use of chemical weapons by Syria in its civil war would be crossing a "red line" that would prompt a swift U.S. response.

Diplomatic front: More talks, but no clear results

On the diplomatic front, U.N. peace envoy Lakhdar Brahimi met Tuesday with members of the National Opposition Coordination Commission at a hotel in Damascus. Commission Chairman Hassan Abdel Azim said possible solutions to the crisis were reviewed with the envoy. The group is seen as a government-approved opposition group or regime front. It is not recognized by other opposition groups, such as the LCC or the Free Syrian Army.

Tuesday's meeting came a day after Brahimi met with al-Assad.

The LCC on Tuesday laid out its demands for peace talks. It said it would reject any initiative that would force Syrians "to choose between accepting unfair compromises or the continuation of the regime's crimes against them." The group also warned against granting the government "more time to continue to destroy and kill."

The LCC said that the president and his officials must leave power in order for any initiative to work, and that any plan to give the government immunity against prosecution would be "immediately rejected, as it threatens the chance for Syrians to succeed in achieving justice."

In Bahrain, the six-nation Gulf Cooperation Council called for an immediate end to violence in Syria, and pledged support for the opposition, Kuwaiti state-run news said.

Members of the group, such as Qatar and Saudi Arabia, have supported the Syrian opposition. The four other Gulf Cooperation Council members are the United Arab Emirates, Kuwait, Bahrain and Oman.