South Korean police have announced new measures to tighten controls on illegal weapons following a recent homemade firearm incident in Incheon.

The National Police Agency said Wednesday that this year’s annual voluntary surrender period for illegal arms will start early, running from August 1 to September 30, with immunity granted to those who turn in weapons during that time.

Authorities will also strengthen monitoring of online content related to firearm manufacturing and are pursuing AI-based systems to automatically detect and request the removal of illegal posts.

Those caught making or possessing homemade guns can face up to 15 years in prison or fines of up to 100 million won, or approximately 72-thousand U.S. dollars.

The move comes after a man in his 60s fatally shot his son using a homemade firearm in Incheon on Sunday, with police later discovering additional similar guns in his car and 15 explosive devices at his home.