Defense Minister Kim Kwan-jin said Friday the military would step up its air defense to counteract North Korean spy drones that have become a new security threat here this week.

“We are working on preparing counteractions (against drones), taking into account that Pyongyang’s drones could potentially carry out suicide-bombing operations upon further development,” Kim said in an interpellation session held at the National Assembly.

The defense minister said that the unmanned aerial vehicles do not yet pose a serious threat, since the photos taken by them are similar in quality to Google satellite imagery. 

Kim added that he cannot rule out the possibility that more drones ― besides the two recently retrieved by the military ― have penetrated the country’s defense system.

The Defense Ministry said it is pushing to purchase advanced low-altitude surveillance radars and anti-aircraft guns to better detect and shoot down aircrafts.

The Defense Acquisition Program Administration recently said it is pushing to resume a surveillance blimp development project that folded last December due to technical problems.

The South Korean military has been drawing fire after two drones were recovered by officials in the past two weeks on Baengnyeongdo Island and in Paju, Gyeonggi Province, which is close to the Demilitarized Zone. Seoul provisionally concluded that the aircrafts were from Pyongyang.

Officials recovered photos from the drones that showed they had flown over Cheong Wa Dae and military facilities.

Although the Defense Ministry said none of those photos have been transmitted to the North, criticism mounted over the military’s apparently poor readiness.

Earlier Friday, a government official said another unidentified aircraft was detected flying over the border island of Baengnyeongdo.

Kim Min-seok, spokesman for the Ministry of Defense, said the military caught a glimpse of the aircraft on its radar before it fired warning shots. He did not confirm whether the unidentified aircraft was another North Korean drone, saying the ministry is considering all possibilities.

Lawmakers from rival parties lashed out at the defense minister and urged him to come up with more comprehensive and preventative measures.

“It is chilling to think how many North Korean drones have flown through our airspace,” said Saenuri lawmaker Lee Cheol-woo during the interpellation session, calling the military “incompetent.”

Opposition lawmakers called for the defense minister’s dismissal, saying he should take responsibility.

“Prime Minister Chung Hong-won should request for President Park Geun-hye to dismiss Minister Kim,” Rep. Jin Sung-joon of the New Politics Alliance for Democracy said.

Rep. Park Joo-sun of the NPAD said the “porous” air defense system is making drones look like stealth jets. “Instead of spending hundreds of billions of won on high-tech weaponry, we should verify how our skies were penetrated by such poorly designed ‘antique’ drones and come up with a solution.”

By Yoon Min-sik (minsikyoon@heraldcorp.com)