Apple Inc. has announced it would \"thoroughly investigate\" an accident in which a woman in northwest China was suspected of being killed by an electric shock when making a phone call with a recharging iPhone 5, state-run Xinhua News Agency reported Monday. The 23-year-old woman in Xinjiang Uygur Autonomous Region was picking up her iPhone 5 to answer a call while the battery was being charged when she was electrocuted and killed last Thursday, police have said, according to the report. But police have not confirmed whether a mobile phone was involved as they continue to investigate the case. Apple said on Sunday in a statement that the company felt \"deeply sorry for the unfortunate accident\" and expressed condolence to the victim and her family. The company would have a thorough probe into the case, and would be in full cooperation with investigations, the statement said. The woman fell to the floor when making a call with her iPhone 5, which was being recharged at the time, her sister said. She bought the iPhone in December at an official Apple store and was using the original charger to recharge the phone when the incident occurred. Experts said mobile phones have a low output of only 3 to 5 volts, which isn\'t enough to harm the human body. People will feel an electric shock at about 36 volts. \"However, if the charger or the circuit has a problem, such as a broken wire, it can lead to a shock of 220 volts,\" a senior physics teacher was quoted as saying.