NEW DELHI: Hazardous smog interrupted the third Test between India and Sri Lanka in New Delhi on Sunday, with players wearing face masks as air quality dipped in the world's most polluted capital city.

Many of Sri Lanka's fielders returned from lunch on the second day of the Test against India wearing masks amid visible haze at the Feroz Shah Kotla stadium.

A short while later play was halted for around 20 minutes as Sri Lanka complained to the umpires about the smoggy conditions.

The US embassy website Sunday showed levels of the smallest and most harmful airborne pollutants in Delhi at 328 -- more than ten times the level considered safe by the World Health Organization.

The match was halted as the umpires consulted the match referee, team doctors and physiotherapists before deciding to resume play.

Play is routinely suspended due to poor weather, low visibility, lightning or rain but a stoppage as a result of pollution is almost unheard of.

"It is definitely a first of its kind," said one commentator on the official television broadcast.

Last month more than 30,000 runners competed in the Delhi half-marathon, despite dire health warnings from doctors who called for the race to be postponed.

Doctors warn that competitive exercise during severe pollution can trigger asthma attacks, worsen lung conditions and increase the risk of heart attacks and strokes.