Police said Monday they will step up efforts to clamp down on online cafes used to plan group suicides, following a spate of such deaths in recent weeks raising fears of a social epidemic.

On Sunday, police interrupted a suicide attempt at a local hotel room in downtown Seoul involving five people who gathered after meeting through an Internet cafe. The group had devised their plan through e-mails and instant messenger services. The Web site's manager, identified by his last name Kim, was booked on suspicion of abetting in the suicide attempt.

"Group suicide is spreading and becoming a thorny issue nationwide," a police official was quoted as saying by Yonhap News Agency. "We will tighten online surveillance and punish operators of suicide cafes without exception."

In the past three weeks, 14 people have been found dead in apparent group suicides, mostly in hotel rooms and in cars parked in secluded areas of Gangwon Province, a remote eastern region populated by resort facilities. Most used charcoal briquettes in closed spaces that caused victims to suffocate from the toxic fumes, police said.

The latest incidents follow earlier high-profile celebrity suicides, some of which also involved use of coal briquettes, stoking fears of copycat suicides.

Popular actor Ahn Jae-hwan, who died after inhaling toxic fumes from burning charcoal briquettes while inside his car, is believed to have suffered for years under mountains of debt.

The death of iconic South Korean actress Choi Jin-sil, who hanged herself in October, sparked a national debate over malicious Internet rumors and the role they played in her suicide.

Jang Ja-yeon, a budding actress, committed suicide in March. An investigation is currently under way on suspicion that her management company forced her to provide sexual favors to influential figures in the entertainment industry.