New York City smog

Smoke from Canadian wildfires shrouded New York in a record-breaking apocalyptic smog Wednesday as cities along the US East Coast issued air pollution warnings and thousands evacuated their homes in Canada.

The smog seen in Istanbul for the last three days is due to intense air pollution, experts have stated, warning that citizens should not spend much time outside in the early hours of the day.

The fog that started to form in the early hours on the first days of the year in Istanbul increased with the sun rising.

Delhi shut down schools until further notice, urged people to work from home and banned non-essential trucks from entering the Indian capital due to dangerous levels of air pollution.

One of the world's most polluted cities and home to some 20 million people, Delhi is cloaked every winter in a thick blanket of smog.

Beijing declared its third major smog alert of 2018, and the second this month, just a day after being named the top performer among 28 Chinese cities that took special measures to rein in pollution.