Rich tributes were paid to the police personnel who sacrificed their lives in the line of duty, on commemoration day held here on Tuesday. State Police Chief Ravada A. Chandrasekhar laid a wreath at the memorial site at the police headquarters in Thiruvananthapuram. Armed police personnel paid tribute and saluted the memory of the police officers who died in the line of duty. One hundred and ninety one police officers from the police paramilitary forces have lost their lives in the line of duty in the last year. The Police Commemoration Day is observed on October 21 every year to pay respects to the 10 policemen who were killed by Chinese troops in an ambush on a police team that went to find missing police personnel at Hot Springs in Ladakh in 1959.