In a statement, the Yemeni clerics described the Saudi-led campaign on Yemen as a violation of the international law.
According to Al-Ahed News website, they also asked all Yemenis to maintain unity and stand against Saudi Arabia's aggression.
Moreover, the clerics called on world Muslims and human rights organizations to stage rallies to mount pressure on Riyadh and its allies.
While the coalition, backed by the US, has been conducting air strikes against the Houthi movement forces and army units loyal to ex-president Ali Abdullah Saleh since March 26, a five-day humanitarian ceasefire is expected to begin on Tuesday.
More than six weeks of deadly aerial attacks on Yemen have killed more than 3,500 people and left some 6,200 others injured.
The Saudi-led coalition, which seeks to restore power to the fugitive former President Abd Rabbuh Mansour Hadi, includes eight other Arab states and is receiving logistical support from the US, Britain and France.