ROUGH CUT (NO REPORTER NARRATION)<br/> <br />North Korea fired more than 100 artillery rounds into South Korean waters as part of a drill on Monday, prompting the South to fire back, officials in Seoul said, but the exercise appeared to be more saber-rattling from Pyongyang rather than the start of a military standoff.<br/> <br />During a press briefing at the Pentagon, U.S. Defense Secretary Chuck Hagel warned North Korea that these actions must stop.<br/> <br />"The North Koreans have to stop these provocative actions. And we've been very clear on that. Obviously when I'm in China, that will be a subject that I will discuss with my counterpart in China," Hagel said.<br/> <br />North Korea also accused the South of "gangster-like" behavior at the weekend by "abducting" one of its fishing boats and threatened to retaliate. The South said it had sent the boat back after it drifted into its waters.<br/> <br />The North had flagged its intentions to conduct the exercise in response to U.N. condemnation of last we
