New Delhi, Jan 9 (IANS): The national capital region (NCR) on Thursday witnessed fog but experience an improved air quality that was recorded under the 'poor' category.

According to the India Meteorological Department (IMD), the minimum temperature was nine degrees Celsius, while the maximum was expected to hover around 16 degrees Celsius, an IMD official said.

The weather office predicted that the region would continue to witness dense to very dense fog in the coming days.

At least 21 Delhi bound trains were delay by up to six hours on Thursday morning.

The air quality of the national capital was recorded under 'poor' category following the rains the city received during the last two days.

According to the Centre-run System of Air Quality and Weather Forecasting (SAFAR), the overall air quality index (AQI) of Delhi was recorded at 211 on Thursday morning.

"The current western disturbance and induced cyclonic circulation is influencing AQI positively. The increase in moisture may lead to foggy conditions. On January 10, the SAFAR model suggests marginal deterioration of air quality and in the poor category," SAFAR said.