South Korean department stores on Friday boosted security measures after copycat crime threats went viral online, following a stabbing rampage at a department store in Bundang, Gyeonggi Province on Thursday.

Lotte Property & Investment, one of the leading department store operators here, on Friday dispatched a security team of 130 members to the area around Lotte Tower near Jamsil Station. Lotte added it has also sent three anti-terrorism agents to search the area.

Jamsil Station was one of the locations that were mentioned in online copycat crime threats. One of the writers threatened to kill 20 people Friday morning at Jamsil Station.

"(We) are increasing searches of the underground shopping area and the nearby region, as well as the plaza area where many people gather for events," an official from Lotte Property & Investment said.

Hyundai Department Store also said the company held meetings on Friday morning to discuss emergency security measures to counter possible accidents.

Shinsegae Department Store said that it will respond to potential accidents in line with its emergency manual.

Department stores here have increased safety measures because the stabbing rampage on Thursday evening took place at a department store near Seoul Metro's Seohyeon Station.

The attack left 14 people wounded, 12 of whom were seriously injured. Of the total, nine were wounded in the stabbing attack and five in the car crash.

After the accident, a series of copycat crime threats were posted online. Among the locations mentioned were the Jamsil, Orion, Gannam and Hanti subway stations.