NEW DELHI: India's capital New Delhi opened its first "smog tower" on Monday aimed at reducing the air pollution blamed for thousands of premature deaths every year, but experts were sceptical.

Concentrations of tiny deadly particles in Delhi's air regularly exceed safe limits by up to 20 times, particularly in winter when its 20 million people are enveloped in a noxious grey blanket of smog.

Forty giant fans on the 25-metre (82-foot) tower will pump 1,000 cubic metres of air per second through filters that halve the amount of harmful particulates in a radius of one square kilometre (0.4 square miles), according to engineers.

"Today is a big day for Delhi in its fight for clean air against pollution," Chief Minister Arvind Kejriwal said after the inauguration near the busy shopping area of Connaught Place.

The installation "is being looked at in an experimental way. We will analyse the data and if it's effective, more towers will be built across Delhi," Kejriwal added.