(Reuters) -Attacks on hospitals, ambulances and other health care facilities in Ukraine have increased rapidly in recent days and the country is running short of vital medical supplies, the World Health Organization (WHO) said on Tuesday. The U.N. agency confirmed on Monday that at least nine people had died in 16 attacks on health care facilities since the start of a Russian invasion of Ukraine on Feb. 24. It did not say who was responsible. The WHO’s senior emergency officer for Europe, Catherine Smallwood, told a news briefing that the tally included incidents where ambulances had been comm…