Afghanistan documented nearly 5,000 deaths attributed to air pollution in 2020, the health ministry told Deutsche Presse-Agentur (dpa).

These deaths were due to respiratory and heart diseases that were considered to be caused by air pollution, ministry spokesperson Masouma Jafari said.

Around 10% of those killed by these diseases in Afghanistan were in Kabul city, the ministry figures show.

The Afghan capital was considered the world's worst polluted city last year and is on track to remain among the most polluted cities in 2021.

According to the air quality index, the air in Kabul becomes "very unhealthy" at night during winter.

The head of Wazir Akbar Khan hospital, Dr. Abdullah Ahmadi, told dpa that the hospital has received more than 600 patients in less than one month.

"An average of 20 patients with respiratory diseases visit our hospital on daily basis," Ahmadi said. "Most of these problems are because of air pollution."

Excessive use of coal, old vehicles that produce a lot of exhaust fumes and unpaved roads are the main contributors to increasing air pollution, an official at the National Environment Protection Agency (NEPA) told dpa.

The problem is exacerbated by electricity shortages, expensive gasoline and low-quality fuel.

Since last year, officials have begun a crackdown on local businesses thought to be the main contributors to air pollution by burning scrap tires and plastics to provide heating.

The air pollution problem is a global challenge. According to the World Health Organization (WHO), air pollution kills an estimated 7 million people worldwide every year.