CNN had some explaining to do on the air Friday morning, following its earlier report that the Coast Guard “tried to prevent a boat from entering a security zone on the Potomac River,” and that shots were fired not far from where President Obama commemorated the attacks on Sept. 11.

The network caused a stir on Twitter with the following: “BREAKING NEWS: Suspicious boat in river near Obama in DC. Police scanner reports of shots fired. Circumstances unclear.”

It turns out the Coast Guard was involved in a training exercise.

Jeanne Meserve, CNN’s homeland security correspondent, went on the air after to explain why the network reported on shots being fired.

“We saw things happening on the water,” she said. “We could see boats racing around. And we were listening to Coast Guard radio traffic.”

Meserve said she heard on the Coast Guard radio that 10 rounds had been fired.

CNN had based its initial story on reports from police scanners that shots had been fired, but had no independent confirmation.

White House press secretary Robert Gibbs told POLITICO that CNN should attend the Coast Guard’s noon press conference where they’ll explain the exercise on the Potomac.

“My only caution would be that before we report things like this, checking would be good,” Gibbs said.

Later, Gibbs and CNN’s Elaine Quijano had a heated exchanged during a gaggle with reporters, where the press secretary said it was “a little hard to divorce the media coverage” from her questions. Gibbs said his criticism wasn’t of her, “just write large at CNN.”

“Look, if anybody was unnecessarily alarmed based on erroneous reporting that denoted that shots had been fired, I think everybody is apologetic of that,” Gibbs said.

CBS News Radio White House correspondent Mark Knoller, on Twitter, said that “some networks have a lot of explaining to do–misinterpreting police scanner messages as shots firect [sp?] by the coast guard. He added: “As Walter Cronkite used to say, get it first, but first, get it right.”

Matt Drudge singled out the network, with a blaring headline: “CNN PANIC IN DC ON 911 ANNI.”

A CNN spokesperson did not immediately respond to a request for comment.

Following the incident, ABC News’ Lisa Stark reported: The Federal Aviation Administration confirmed to ABC News that flights departing from the Washington D.C. Ronald Reagan National Airport were stopped for 20 minutes as a precautionary measure after media reports of shots fired by the Coast Guard on the Potomac River.

FAA officials say 17 outbound flights were affected but arrivals were not impacted. Departures stopped at around 10:08 a.m. and resumed at 10:29 a.m.

(Source: Politico)