Authorities in Indian capital Delhi unsuccessfully carried out a cloud seeding trial, which is the science of altering clouds to make rains, to tackle the city's worsening air pollution on Tuesday.
Cloud seeding is done by firing small particles - usually silver iodide - into clouds to produce rain. The technique is used around the world, but experts doubt its efficacy as a long-term air pollution control measure.
A team of the Indian Institute of Technology (IIT) Kanpur and the Delhi government carried out the trial over several neighbourhoods, as thick smog enveloped the city.
But the attempt - the first in 50 years - was "not completely successful" due to the lack of moisture in the air.
Over the past two weeks, Delhi's Air Quality Index (AQI) - which measures the level of PM 2.5 or fine particulate matter in the air that can clog lungs - has been hovering between 300 and 400, which is nearly 20 times the acceptable limit.
