Saudis are some of the world’s most ruthless figures. They rule with an iron fist.

They tolerate no opposition. They partner with Washington’s regional wars.

They were caught red-handed supplying Syrian takfiris with chemical weapons – used against defenseless civilians.

They’re at it again. Overnight reports indicate they attacked Yemen’s Saada province with banned chemical agents.

Toxic gas left scores of Yemeni civilians dead or injured. The exact number isn’t known so far.

Witnesses and aid workers said white smoke rose from Saudi terror-bombing. Injured victims experienced suffocation, nausea and diarrhea.

Days earlier, Houthi rebels intercepted Saudi trucks carrying chemical agents.

Yemeni General Khalid al-Barayemi said they were heading for areas controlled by terrorists.

Substances seized is used for producing lethal sarin gas. Al-Barayemi believes Turkey is complicit in supplying chemical agents under the cover of humanitarian aid.

World leaders able to stop this horror support it – mindless of naked aggression harming defenseless civilians most of all.

Nightmarish conditions exist throughout much of Yemen. ICRC officials said they were denied access to Maareb in central Yemen – where large numbers urgently need medical treatment.

ICRC’s Cedric Schweizer said “(w)e very much regret the lack of access to Maareb, where hospitals face shortages of medical equipment.”

“The wounded, including civilians and combatants, cannot get the lifesaving treatment they need.”

Similar conditions exist throughout much of the country. Overwhelming needs of virtually everything exceed the best humanitarian efforts to help.

Blockading air, land and sea makes it impossible to deliver enough desperately needed food, water, medical and other vital supplies.

Since Saudi-led terror-bombing began in late March, over 150,000 Yemenis have been displaced, according to OCHA.

Thousands more flee homes for safety daily. There’s nowhere to hide. No safe havens exist.

Saudi terror-bombing deliberately targets civilian sites – including with banned weapons. Naked aggression is mass-murdering and injuring thousands.

Saudis, Washington and Israel are the main backers of regional terrorist groups – IS, Nusra Front, Al Qaeda and others.

They supply them with funding, weapons, munitions and other aid. Saudis provide lethal chemical agents. Maybe Washington and Israel do the same thing.

Eighteen Western Yemeni scholars published an open lettercondemning Saudi-led terror-bombing.

They called it “illegal under international law.” They called for a Security Council resolution “demanding an immediate, unconditional ceasefire.”

They accused Saudis of deliberately targeting “schools, homes, refugee camps, water systems, grain stores and food industries.”

They warned “(t)his has the potential for appalling harm to ordinary Yemenis as almost no food or medicine can enter.”

“As specialists we are more than aware of internal divisions within Yemeni society, but we consider that it is for the Yemenis themselves to be allowed to negotiate a political settlement,” they said.

Signatories include:

Robert Burrowes, University of Washington

Steve Caton, Harvard University

Sheila Carapico, University of Richmond

Paul Dresch, University of Oxford

Najam Haidar, Barnard College

Helen Lackner

Anne Meneley, Trent University

Brinkley Messick, Columbia University

Flagg Miller, University of California-Davis

Martha Mundy, London School of Economics

Thanos Petouris, SOAS-University of London

Lucine Taminian, The American Academic Research Institute in Iraq

Gabriele vom Bruck, SOAS-University of London

Lisa Wedeen, University of Chicago

Shelagh Weir

John Willis, University of Colorado

Stacey Philbrick Yadav, Hobart and William Smith Colleges

Sami Zubaida, Birkbeck College, London

Expect their plea to fall on deaf ears in Washington, other Western capitals and Riyadh.