Air pollution hit 'very high' levels yesterday for the ninth time in the last six weeks and forecasters predicted unhealthy smog would reappear today.

The bad air is the result of light winds which are unable to blow away pollutants, government officials said.

Roadside pollution monitoring stations in Causeway Bay recorded a level of 111, prompting a warning for people with heart and breathing problems to re duce outdoor activities. Monitoring stations at Kwai Chung and Central showed similar pollution levels.

An Environmental Protection Department spokesman said high levels of pollution were expected again today.