Riyadh (AFP) - Saudi Arabia suffered its worst civilian death toll Tuesday in cross-border shelling from Yemen as an anti-rebel coalition it leads launched an investigation into a deadly strike on a hospital.
A rocket fired by rebels in Yemen killed seven civilians in Najran city in the highest reported number of non-combattant casualties in the kingdom's south since the Arab coalition intervened in Yemen 17 months ago.
"It killed four citizens and three residents," the civil defence spokesman in Najran city said of the rocket strike, the official Saudi Press Agency reported.
The attack came after the coalition launched an investigation Tuesday following international condemnation of an air raid on Monday that Doctors Without Borders (MSF) said killed 14 people at a hospital it supports.
Another 24 people were wounded in the strike that hit the hospital on Monday in Abs in the rebel-held northern province of Hajja, the Paris-based aid agency said.
An MSF staffer was among the dead, it said.
The hospital strike was the latest in a series of coalition raids that allegedly hit civilian facilities -- including a school on Saturday where 10 children were killed.
The coalition began its bombing campaign in March last year after Iran-backed Shiite Huthi rebels seized large parts of Yemen, including the capital Sanaa.
It stepped up air strikes this month after UN-mediated peace talks between the rebels and Yemen's internationally backed government were suspended.
The coalition's spokesman accused the Huthis of using the three months of negotiations to rearm.
- 'Deceiving people' -
"They were deceiving people by this negotiation, to re-organise their force, re-supplying their forces and getting back to fighting," Brigadier General Ahmed Assiri said.
He said the coalition would do "whatever it takes" to restore security in Yemen.
MSF said Monday's attack was the fourth on one of its facilities in less than a year.
At the time of the strike, the hospital was "full of patients recovering from surgery, in maternity, newborns and children in paediatrics", it said.
MSF said the hospital's GPS coordinates "were repeatedly shared with all parties to the conflict, including the Saudi-led coalition, and its location was well-known".
Teresa Sancristoval of MSF's emergency unit in Yemen said: "What we need to see is proof of intent and a commitment that there will be no more air strikes on medical facilities, staff, and patients."
A US State Department spokeswoman said: "Strikes on humanitarian facilities, including hospitals, are particularly concerning."
UN Secretary General Ban Ki-moon said he was "deeply disturbed" by the intensification of air raids in Yemen.
"Hospitals and medical personnel are explicitly protected under international humanitarian law and any attack directed against them, or against any civilian persons or infrastructure, is a serious violation of international humanitarian law," Ban said.
Amnesty International said the bombardment "appears to be the latest in a string of unlawful attacks targeting hospitals, highlighting an alarming pattern of disregard for civilian life".
- Mounting criticism -
A Joint Incidents Assessment Team (JIAT), composed of members of the coalition, said it "has urgently launched an independent investigation" into the strike and promised to announce its findings.
The JIAT was set up following mounting criticism of the civilian death toll from the bombing campaign.
Earlier this month, it acknowledged "shortcomings" in two of eight cases it investigated of strikes on civilian targets in Yemen.
In one case, the team held the coalition responsible for hitting an MSF-run hospital but accused the rebels of having used the facility as a hideout.
The team is also investigating Saturday's strikes in the rebels' northern stronghold of Saada, which MSF said hit a school but the coalition claimed targeted a rebel training camp with child soldiers.
A rebel council in Sanaa condemned the hospital strike and called on the UN to form an "independent committee to investigate" coalition "crimes".
Coalition strikes on Tuesday struck Abs, Saada and areas surrounding Sanaa, military sources and residents said.
The coalition resumed raids on Sanaa on August 9, almost three days after the talks were suspended, with one strike reportedly hitting a food factory, killing 14 people.
That forced the closure of Sanaa airport, but its director said three flights -- carrying World Food Programme (WFP) and Red Cross employees as well as humanitarian aid -- landed on Tuesday.
The Sanaa-based civil aviation authority Tuesday said passenger flights to the airport remained suspended.
The UN says more than 6,500 people, mostly civilians, have been killed since last March and more than 80 percent of the population needs humanitarian aid.