The World Health Organization (WHO) on Tuesday warned lack of funding has continued to force the health facilities in Yemen to shut down, leaving civilians without access to critical, life-saving health care.

WHO spokesperson Tarik Jasarevic on Tuesday told press that almost 23 percent of all health facilities in Yemen are currently non-functional or partially functional as a direct result of on-going violence, and additional facilities continue to close down week by week.

Meanwhile, a total of 15.2 million people, including 1.2 million internally displaced persons, are in need of life-saving assistance in Yemen, especially in Aden, Abian, Taiz and Sa'ada governorates.

Amidst funding shortages and inaccessibility challenges, WHO has supported the Ministry of Health and partners with over 181 tonnes of medicines and medical supplies for more than 3 million people, including for trauma care, non-communicable diseases, laboratory and blood banks.

Jasarevic said while health needs continue to grow, funding for an effective health response remains limited.

"Out of 151 million U.S. dollars required to meet the health needs of internally displaced persons in Yemen until the end of 2015, only 23 million USD has been received, leaving a funding gap of 85 percent," he noted.

The spokesperson warned if WHO does not receive much needed funds in the next coming months, a number of critical health care services will be forced to shut down.