SANAA, Feb. 12 (Xinhua) -- H1N1 flu has killed 139 people in Yemen's northern provinces since 2018, the local health authorities said in a statement on Tuesday.

In January, the Houthi-controlled health authorities reported the deaths of 22 people, and the infection of 107 others, raising concern in the war-torn country.

Most cases were reported from the capital Sanaa, Amran and Ibb provinces. There was no comment yet from the World Health Organization (WHO) on the report.

The country's health system has collapsed in the four-year-long civil war, triggering what the United Nations calls the world's worst humanitarian crisis.

Cholera epidemic in Yemen set the world's highest record with the infection of 1 million people and confirmed deaths of over 2,000 others, according to WHO.

Saudi Arabia has been leading an Arab military coalition that intervened in Yemen in 2015 to support the government of President Abd-Rabbu Mansour Hadi after the Houthi rebels forced him into exile and seized much of the country's north, including Sanaa.