LUCKNOW : The death toll due to coronavirus in Uttar Pradesh on Thursday rose to 345 after it reported a record 24 fatalities, while 478 fresh cases pushed the tally in the state to 12,088, officials said here.The state has 4,451 active COVID-19 cases and 7,292 patients have recovered, Principal Secretary, Health, Amit Mohan Prasad told reporters here.He said 15,079 tests were conducted in UP on Wednesday, which is so far the highest in the state.Prasad said accredited social health activists (ASHAs) were visiting villages to trace migrants who have returned from other parts of the country and till now over 15 lakh migrant workers have been tracked.