Fixed-line internet services provided by South Korea's three major telecom companies experienced partial disruptions Thursday, apparently due to an error that occurred during a firmware update. Telecom industry sources reported nationwide service disruptions to wired internet networks by the three telecom companies starting at 5 p.m. Industry insiders believe the issue was caused by an error during a firmware update process involving a company that supplied access point equipment to the telecom operators. Subscribers using these devices were unable to access certain websites, including those of government-run "go.kr" domains. The company supplied the equipment to KT Corp. and SK Broadband Co., but subscribers of LG Uplus Corp. also experienced disruptions as some users personally purchased and installed equipment using the same chip. However, the error apparently did not lead to a large-scale outage, as the supplier is not a top-tier player, according to telecom sources. "We are responding to clients t hrough customer centers and websites and are currently making efforts to promptly normalize the services," an official from one of the telecom companies said. The telecom companies and communications authorities immediately launched an investigation to assess the situation. The service operators were also considering the possibility of a hacking attack as the cause of the disruptions, industry sources said. Source: Yonhap News Agency