South Korea Boosts Security for Politicians as New Threats of Violence Emerge

SEOUL—South Korea beefed up security for prominent political figures as new threats of violence materialized against top officials, including the opposition-party head who was stabbed the prior day.

The left-leaning Democratic Party of Lee Jae-myung, who was attacked at a public event Tuesday, said several other individuals had threatened to kill the politician, and it vowed to track down the perpetrators and take legal action. The 59-year-old Lee was recovering on Wednesday at a hospital in Seoul after receiving emergency vascular surgery.