The United Nations children's agency says it has started paying over 136,000 teachers and school-based staff in Yemen who haven't received their salaries in over two years.

UNICEF says Sunday its scheme covers staff in over 10,300 schools and will benefit an estimated 3.7 million children. It says over 2 million children are already out of school, out of seven million school-aged children.

Geert Cappelaere, UNICEF regional director for the Mideast and North Africa, says eligible teachers and staff will be paid $50 monthly, with the first payment cycle reaching more than 97,000 professionals.

Yemen has been embroiled in a stalemated war pitting a Saudi-led coalition against Shiite rebels, since March 2015.

Cappelaere says one in five schools in Yemen can no longer be used because of the war.