At least 18 civilians have been killed in Saudi Arabia’s multiple aerial strikes across war-torn Yemen during the past 24 hours.

Saudi fighter jets bombarded Khawlan al-Tayyal district in the western Yemeni province of Sana'a on Friday, killing at least 11 people, including women and children, and injuring a number of others, including two children.

The victims were all travelling in a vehicle when it came under Saudi fire, Yemen's al-Masirah television channel reported on Friday.

The Saudi warplanes also launched several airstrikes on different localities in the northwestern province of Sa'ada. Initial reports said at least two people were killed in the province's Ghamar district as a result of the airstrikes.

Elsewhere in the west-central province of Ma'rib, at least five other Yemenis lost their lives when Saudi jets pounded Sirwah district.

Saudi warplanes also bombarded areas in the northern province of Jawf and in the western provinces of Amran and Hajjah, but there have been no immediate reports about the possible casualties.

Saudi targets civilians

Meanwhile, the results of a survey published by The Guardian on Friday showed that over a third of the Saudi airstrikes on Yemen target civilian sites, including homes, schools, hospitals and mosques.

The survey, which was conducted by the Yemen Data Project, comprising a group of academics, human rights organizers and activists, has examined more than 8,600 aerial assaults from March 2015 to the end of August.

The report also shows that one particular school, in Dhubab district located in the southwestern province of Ta'izz, was hit repeatedly nine times, and a market in Sirwah district located in Ma'rib province was struck 24 times.

According to the survey, the Saudi war machine hit more non-military sites than military ones during the past five months.

Back in June, the UN blacklisted Saudi Arabia after concluding in a report that Riyadh was responsible for 60 percent of the 785 deaths of children in Yemen last year.

A few days later, however, the world body removed Riyadh from the blacklist, citing threats by the regime and its allies to cut off funding to many UN programs. The move triggered an outcry from human rights groups.

Saudi Arabia has been repeatedly criticized by rights groups over civilian casualties caused by its aerial campaign against Yemenis.

The Arab kingdom has been incessantly pounding Yemen since March 2015, with the UN putting the death toll from the military aggression at about 10,000. The offensive was launched to reinstate Abd Rabbuh Mansur Hadi, a Saudi ally who has resigned as Yemen’s president.

UN Humanitarian Coordinator for Yemen Jamie McGoldrick said last month that the death toll from the Saudi military aggression could rise even further as some areas had no medical facilities, and that people were often buried without any official record being made.