Nearly one million doses of under-year vaccine arrived in Yemen's rebel-held capital Sanaa on Thursday, local health authorities said in a statement.

The shipment arrived in Sanaa airport by a cargo plane belonging to the United Nations Children's Fund (UNICEF), the statement said.

The doses are routine immunization vaccines for children under one year.

The vaccine will be throughout all Yemeni provinces.

The shipment includes 931,950 vials of Pentavalent vaccine and 92,150 vials of pneumococcal vaccine.

The UNICEF office in Sanaa did not immediately respond to a request for comment.

Yemen is the world's worst humanitarian crisis. Nearly 80 per cent of the total population, 24.1 million people, require some form of humanitarian assistance and protection.

Ten million people are a step away from famine and starvation and 7 million people are malnourished, according to the UN Humanitarian Coordinator in Yemen.

Yemen is suffering a long-running civil war between the government and Houthi rebels, which humanitarians said has brought the country to the brink of famine.