Al-Nusra and several other groups announced their opposition to a new anti-government coalition last month . ` ` Those responsible should be held accountable '' for use of chemical weapons , it says . At least 142 people are killed Monday across Syria , the opposition says . It accuses the United States of setting it up to be framed on chemical weapons .
` ` Those responsible should be held accountable '' for use of chemical weapons , it says . At least 142 people are killed Monday across Syria , the opposition says . It accuses the United States of setting it up to be framed on chemical weapons .