July 12 (Reuters) - Myanmar"s military authorities pledged on Monday to ramp up oxygen supplies to help treat COVID-19 patients, as residents described their struggle to secure supplies to save loved-ones from a record-setting wave of infections. Photographs on social media showed long queues of residents in Myanmar"s biggest city Yangon trying to refill oxygen cylinders. In the city"s Insein district, one resident reached by telephone said she had rented a cylinder and refilled it at the weekend after her father"s oxygen level dropped. She was now desperate to get more. "What if we can"t find oxygen and... my father dies because of it?" said the 24-year-old, who asked not to be identified. Another resident said due to shortages of equipment some people were now using oxygen cylinders from the welding industry. Ousted leader Aung San Suu Kyi, who has been detained since a Feb. 1 coup, was "gravely concerned" about the worsening coronavirus situation, her lawyer said on Monday. Myanmar saw a record 80 coronavirus deaths and 5,014 new cases on Monday, with positive results from more than a third of people tested, state-run MRTV said. Myanmar is in the midst of its most serious wave of infections. Some health experts say the real rate of infection is likely to be far higher given a collapse in testing. Health workers had joined a civil disobedience movement to protest against the ousting of Suu Kyi, whose government had brought two previous waves of infection under control. A doctor who gives phone consultations to COVID-19 patients said he knew of many cases of people dying across Myanmar because they couldn"t get oxygen in time. Army spokesman Zaw Min Tun told a news conference on Monday military authorities were preparing 14 locations for COVID-19 treatment in military hospitals across Myanmar. He said oxygen plants would be operated at full capacity, while confirming media reports that sales to the public by some private providers had been restricted. At the same news conference, a representative from the health ministry said oxygen supplies needed to be supervised in order to avoid hoarding. "Some people may not have COVID-19 but store a large amount of oxygen tanks in their homes," said the official. Military chief Min Aung Hlaing said a donor, whom he did not name, had provided funding for an oxygen plant, for which construction would be finished within a month. He assured the public there was sufficient oxygen supply, but said the situation was being distorted and exploited for political gain. "There is enough oxygen in the country. Some people bought oxygen as they are worried," he said on MRTV. "I want to tell the people not to be afraid or fear."