A couple in Chifeng, the Inner Mongolia autonomous region, swept streets for 23 years to pay off debts they ran up for hospital treatment for their two sons.

The 64-year-old Xu Cai and 62-year-old Liu Guiqin borrowed 80,000 yuan ($12,900) from friends and relatives 23 years ago to send their two sons to hospital. Their sons, then aged 17 and 18, were diagnosed with a brain tumor and nasopharyngeal cancer. Both passed away after 20 months’ treatment.

Though many people said the couple did not need to repay the debt, Xu and Liu left their home village of Shuiquan and got jobs sweeping streets in Chifeng to repay the money. They got up at 3 am each day to start work.

The couple said they "felt relieved like they had never felt before" after paying off the debt.