South Korea will step up security efforts to prevent vandalism of its historic sites, following nighttime graffiti incidents on the walls of Gyeongbokgung two weeks ago, according to the Cultural Heritage Administration on Thursday.

The measures unveiled by the CHA will center on increasing police patrols and the number of surveillance cameras, reaching up to 110 overall.

According to the agency, the country’s popular royal palaces as well as tombs and a shrine in Seoul -- all connected to the Joseon era (1392-1910) -- will be placed under the improved protections, starting with the main palace Gyeongbokgung.

“In addition to such preventative steps introduced today, we’re also seriously considering rewarding those who alert the authorities of violations or violators,” Choi Eung-chon, the agency chief, said during a briefing.

“Repairing damage done to national heritage sites is an arduous task,” Choi said in reference to the potential of launching a reward system. Choi noted, however, that the agency still needs more time to weigh up all the pros and cons.

Sections of the walls at Gyeongbokgung -- a national treasure that attracts millions of visitors annually in the heart of Seoul -- were vandalized with spray-paint on two occasions in mid-December. The first incident was reportedly committed by two minors, while the second was done by a 28-year-old man, in what was believed to be a copycat.

The agency has so far spent at least 20 million won ($15,264) cleaning the damaged areas of Gyeongbokgung -- the entrance to Yeongchu Gate, the palace’s western gate, and the side gate of the National Palace Museum. Cleaning up graffiti spreading across 36.2 meters in total had required daily average manpower of 29.3 for eight days, according to the agency.

“About 80 percent of the work is done for now,” the CHA said, suggesting the cleanup process is not complete. “We will reassess the total cleanup costs and seek damages from the suspects.”

The CHA added that it will work with municipalities to decide which historic sites need more surveillance cameras and security staff.

“The (recent) vandalism incidents have made us all rethink the way we preserve our national heritage,” Choi told reporters. “We will work to prevent potential crimes and to preserve what we have, so people feel proud of the country, a cultural powerhouse.”