As many as 5.1 million Yemenis in need of aid live in areas where humanitarian access is difficult, the United Nations country Office for Coordinating the Human Affairs (OCHA) said on Twitter.

OCHA explained that those in need live in 75 inaccessible areas in Yemen.

The United Nations has repeatedly complained that its field teams face difficulties in their attempts to reach certain areas and obstructions to aid deliveries.

According to previous UN reports, nearly 24 million Yemenis – about 80 per cent of the population – are in need of humanitarian assistance, while millions are on the verge of famine.

Impoverished Yemen has remained in a state of civil war since 2014, when Houthi rebels overran much of the country, including the capital Sanaa.

In 2015, Saudi Arabia and its Arab allies launched a massive air campaign aimed at reversing Houthi military gains and shoring up Yemen’s embattled government.

According to UN officials, more than 50,000 people have been killed in the war, while more than 11 per cent of the country’s population has been displaced.