By Sami Aboudi

DUBAI (Reuters) - Saudi Arabia's most senior cleric has urged businessmen and banks to set up a fund to help soldiers stationed along the southern border with Yemen to pay their bills back home, Saudi media reported on Thursday.

The call reflects growing criticism of the Saudi business community seen as not doing enough for the country at a time when a drop in oil prices has slashed the kingdom's revenues and started to affect living standards.

Saudi Arabia waded in Yemen's civil war last year at the head of an Arab coalition trying to restore the recognized government to power. Hundreds of people, many of them Saudi soldiers and civilians, have been killed in cross-border raids by Houthi rebels since March last year.

Speaking in a weekly radio broadcast from the Muslim holy city of Mecca, Grand Mufti Sheikh Abdulaziz bin Abdullah Al al-Sheikh said Saudi soldiers were risking their lives "to defend their religion and country."

"Businessmen ... must come forward as donors and contribute from their wealth to help those at the border," al-Sheikh said, according to the semi-official al-Riyadh newspaper.

The grand mufti said the state was doing its part. "It has ... spent money on the children of those fighters in the defense of the homeland ... and cared for their families, especially the martyrs," he said.

"Non-governmental institutions of all kinds, including banks, must also show an honorable stand," he added.

The world's top oil exporter has been squeezed by a sharp drop in crude prices and its state budget ran a deficit of nearly $100 billion last year.

Social welfare has become more politically sensitive in Saudi Arabia since uprisings elsewhere in the region in 2011.

In 2014, Prince Muqrin bin Abdulaziz, who then was the second in line to the Saudi Arabian throne, denounced banks in the kingdom for contributing too little to society compared to what they took in.

Saudi media have frequently published reports of soldiers and border guards facing difficulties paying debts to banks, and of Prince Miteb bin Abdullah bin Abdulaziz, the National Guards minister, of stepping in to pay personal debts of scores of conscripts.

Akhbar24.com in June ran a satirical video of a soldier pushing a landlord to duck gunshots as the two discussed late house rent payment.

Saudi Arabia's deputy crown prince, Mohammed bin Salman, who oversees the kingdom's economy, unveiled plans in April aimed at ending the kingdom's "addiction" to oil and transform the economy.

(Additional reporting by Marwa Rashad Editing by Tom Heneghan)