TEHRAN, Iran - Iran's opposition leader has criticized President Mahmoud Ahmadinejad over his dismissal of new UN sanctions against Iran, calling such an attitude a "treason to the Iranian nation."

Mir Hossein Mousavi said in an article posted on his website Kaleme late Wednesday that it's wrong to "want to relieve the minds of the people with witticism."

He is apparently referring to Ahmadinejad's description of the UN sanctions as "annoying flies" and a "used tissue." Mousavi did not directly mention Ahmadinejad or the president's remarks on the sanctions.

The United Nations in early June slapped a fourth round of sanctions on Tehran. The West accuses Iran of seeking to develop atomic weapons, a charge that Iran denies.