North Korea warned the South that any repeat of what it deemed a violation of its airspace would trigger a "terrible response" after a senior Seoul official expressed regret over an alleged drone incursion by civilians.

Add Yahoo as a preferred source to see more of our stories on Google. The Federal Aviation Administration's temporary flight restriction has left lingering questions about what briefly caused the halt of flights at the El Paso International Airport, despite administration officials saying the closure was because of Mexican cartel drones.

Kerry Breen is a news editor at CBSNews. com. A graduate of New York University's Arthur L. Carter School of Journalism, she previously worked at NBC News' TODAY Digital.