Schools remain closed in Iran's Tehran and several other cities on Wednesday as severe air pollution continued to grip the country. Thick smog has blanketed the capital for more than a week, prompting authorities to urge residents to stay home. The air pollution index stood at 162 on Wednesday. Critics have blamed the government for burning mazut, a heavy, low-quality fuel oil used in power plants instead of natural gas. The government has denied using the fuel in Tehran.
