Iran says the hike Saudi Arabia's bombardment of civilian targets in Yemen shows the coalition's frustration in falling short of the goals.
"The increased hike in Saudi Arabia's bombardment of residential areas such as Sa'ada and a refugee bus in Hudaydah shows their frustration in not being able to reach their goals in Yemen," said Iranian Foreign Ministry Spokesman Bahram Qassemi on Tuesday.
While slamming Saudi Arabia and its allies actions, Qassemi further called UN to halt the kingdom's atrocities in Yemen, especially the killing of women and children.
Earlier in the day, at least nine civilians have been killed and nearly a dozen others sustained injuries after warplanes belonging to a Saudi-led military coalition struck a bus carrying internally displaced persons (IDP) in war-battered Yemen’s western province of Hudaydah.
Yemen's Arabic-language al-Masirah satellite television network, citing its correspondent in the area, reported on Tuesday that the deadly airstrike hit the bus on a road linking the two towns of Jarrahi and Zabid earlier in the day, adding that three of the dead had been torn to pieces beyond recognition.
Saudi coalition responsible for child deaths in Yemen: UN
Meanwhile, the UN's annual "Children and Armed Conflict" report has shown that a total 1,316 children killed and maimed in the Yemen in 2017.
It noted that out of the 552 children killed (398 boys, 154 girls), the majority were killed in result of action carried out by the coalition, which was also responsible for 300 child injuries.
Saudi Arabia and its allies launched a brutal war on Yemen in March 2015 to reinstall the Hadi regime and crush the popular Houthi Ansarullah movement.
The Yemeni Ministry of Human Rights announced in a statement on March 25 that the war had left 600,000 civilians dead and injured until then.
The Saudi aggression has also taken a heavy toll on the country's facilities and infrastructure, destroying many hospitals, schools, and factories.
Since 2016, the impoverished nation has also been grappling with a deadly cholera outbreak, which has already killed thousands of people.
Several Western countries, the United States and Britain in particular, are accused of being complicit in the aggression as they supply the Riyadh regime with advanced weapons and military equipment as well as logistical and intelligence assistance.