By Sebastien Malo

NEW YORK (Thomson Reuters Foundation) - Medical charity Medecins Sans Frontieres (MSF) said on Monday that 13 people including children had died in the bombing of a hospital in northwestern Syria, describing the weekend attack as an "outrage" which violated international law.

MSF said the air strikes had destroyed most of the hospital which specialized in children's medicine and served some 70,000 people in the town of Meles in rebel-held Idlib province.

Five children and two women were among nine patients who died, in addition to four hospital staff, said MSF. Another six employees were wounded.

Over the weekend the Syrian Observatory for Human Rights, a British-based body which monitors the war in Syria, put the death toll at 10.

MSF, which supports the hospital, said the strikes wrecked medical devices, the operating theater, pediatric and intensive care units, ambulances and the facility's generator.

The medical charity said two aerial strikes had hit the hospital directly and two hit the immediate vicinity. It could not identify who was behind the bombing.

Syrian government and allied Russian military planes operate in Syria. The Syrian government has also accused rebels of hitting medical targets in the city of Aleppo.

The attack on the Meles facility - the biggest referral hospital in the area - has left much of the neighboring population without access to healthcare, said Silvia Dallatomasina, a medical manager for MSF operations in northwestern Syria.

Humanitarian groups have repeatedly called for a halt to strikes on medical facilities.

"Bombing cannot be indiscriminate in areas in which there is a civilian population," Dallatomasina told the Thomson Reuters Foundation by phone.

MSF said the hospital had provided emergency care or consultations for around 250 patients a day, many of them women and children.

Nearly 1,000 people have been killed in attacks on health centers worldwide over the past two years, almost 40 percent of them in Syria, the World Health Organisation (WHO) said in May.

(Reporting by Sebastien Malo, Editing by Emma Batha. Please credit the Thomson Reuters Foundation, the charitable arm of Thomson Reuters, that covers humanitarian news, women's rights, trafficking, property rights and climate change. Visit http://news.trust.org)