Press TV- The Iranian capital is once again suffering from poor air quality and countermeasures such as the closure of schools do not seem to have helped much in alleviating�the problem.

Despite the closure of kindergartens and elementary schools on Saturday, air pollution stubbornly remained at an alarming level in Tehran. This is while schools and administrative offices are also closed in Iran on Fridays.

The capital's Air Quality Index (AQI) was reported at 154 and declared as �unhealthy� for people of all ages and health conditions.

Mohammad Rastegari, the deputy for monitoring at Iran's Department of Environment, however, said that schools will be open on Sunday given forecasts of a relative improvement in air quality.

He said Tehran�s AQI will still show �a high figure� for Sunday but will be lower than that of Saturday.

The megacity of Tehran, with an estimated population of 14 million people, is currently shrouded in a thick grey blanket of smog and suffering low visibility.

Emergency services are on full alert and residents, especially those with cardiac and respiratory problems and pregnant women, have been highly advised to remain indoors.

Pollution levels like the ones recorded in India and China, heavy congestion and cold weather normally cause brown-white smog in Tehran in autumn and winter days each year.

Many blame the quality of gasoline and substandard cars for the poor air quality in the sprawling city.