After a car rampage and two stabbings in and around the South Korean capital that shocked the nation in the past month, at least seven people have been arrested on suspicion of making threats to carry out similar acts, police said Saturday.

Many of the arrests came days after 14 people were injured in an episode in Seongnam, a city southeast of Seoul, that authorities said was being treated as an "act of terror.” The assailant in that case drove a car onto a sidewalk near a subway station, injuring five people, then went into the station and stabbed nine others.

Another stabbing attack in Seoul on July 21 left one person dead and three others injured. The latest arrests in connection with the murder threats are part of police efforts to restore the public’s sense of security.