Kuala Lampur, April 6 --  

SEOUL, April 6 - South Korean President Lee Jae Myung expressed regret to Pyongyang today over drones sent into North Korea earlier this year, actions he called "irresponsible".

Seoul initially denied any official role in the January drone incursion-with authorities suggesting it was the work of civilians-but Lee said a probe had revealed government officials had been involved.

The North warned in February of a "terrible response" if it detects more drones crossing the border from the South, prompting Seoul to investigate the claims.

Pyongyang said it downed a drone carrying "surveillance equipment" in early January.

Photos released by state media showed the wreckage of a winged craft scattered across ...