Police said Sunday that they had opened investigations into 46 people on suspicion of making online murder threats, as fear grows among South Koreans following the back-to-back knife attacks.

One suspect in Seoul, who threatened to kill people in Sillim-dong, in Gwanak district, southern Seoul, has been referred for prosecution, and another based in Busan has been handed over to the military police.

Following the deadly knife attack Thursday night in a shopping mall in Bundang, an expensive neighborhood in Gyeonggi Province, many Koreans have expressed fear that they could be the next victim of a stabbing, as threats to commit copycat crimes have proliferated online. Most of them have indicated Seoul -- which has the most foot traffic -- as the targeted location of the attacks.

Most of the posts were uploaded between Thursday night and Saturday on websites such as DC Inside -- a leading Korean internet forum, online internet communities for university students and X, formerly known as Twitter, according to police.

To prevent further tragedies from happening, police said they would beef up efforts in monitoring the internet and continue work to track down the authors of the posts. Police have also launched a special team to deal with online murder threats. The presidential office said Sunday that police dispatched officers, commandos and detectives to 89 areas targeted as locations of stabbing attacks.

A victim of the Bundang attack, reportedly in her 60s, was pronounced dead at a hospital at around 2 a.m Sunday, according to Gyeonggi Nambu Provincial Police, which is currently investigating the case. Thirteen people are currently being treated for injuries after the attack. Among them, eight were in critical condition as of Sunday morning, police said.

On Saturday, a formal arrest warrant was issued to the 22-year-old suspect surnamed Choi by the Suwon District Court on suspicion of attempted murder, citing the risk of fleeing.

Left in nightmare

Joo, a 20-something-year-old university student who wished to be identified by his surname, found himself “shaking like a leaf” after hearing that a high school teacher in Daedeok-gu, Daejeon, on Friday was stabbed near a school staff room by a person who sneaked into school unannounced.

For a long time, Daejeon has been known to be serene and a city of “no violence,” Joo said of his hometown. But he said he is worried that he could also be the target of an attack one dat.

“I am having a hard time taking in what happened that day at my school. My friends are also having difficulties reeling from the news,” he told The Korea Herald.

Oh Myeong-a, a 41-year-old mother of two children, also feels on edge regarding knife crime and schoolchild safety as her daughters are young.

“How are we supposed to raise our children and give them freedom in a dangerous society? Working moms, in particular, are extremely afraid as we have to send our kids alone to schools and private academies. We will also be the last ones to be in touch when such incidents occur to our child or at schools,” she told The Korea Herald.

She said the so-called “mudjima,” or “don’t ask why” attacks -- those with no obvious motive or connection to the victim, had become a grave social problem.

“Societies have become violent, so I hope the government will find the exact cause of the incidents and why these crimes have increased. What if it becomes a monthly occurrence?” she added.

For Yoon, a 23-year-old university student in Seoul, the knife attacks were a “wake-up call” that he should not walk around unarmed.

“It’s the ugly truth, but before, women were usually the main targets of such crimes. But now, burly young men could also be targeted if they are defenseless. As a male in his 20s, I felt the need to learn how to arm myself with self-defense products while traveling and taking public transportation,” he told The Korea Herald.

“It’s scary how social phobia and personality disorders are giving rational purpose to the assailants to target the innocent. But I want them to know that a justifying factor doesn’t exist. They should pay the price for their wrongdoings,” Yoon added.

Kim, a 20-something university student in Seoul, told The Korea Herald that citizens should be allowed to act in self-defense to keep themselves and their surroundings safe from knife-wielding attacks.

“When we’re in trouble, or somebody around us needs urgent help or are in danger, we should be given the right to punch the attackers’ face or knee them in the stomach so that we can protect each other at all costs,” Kim said.