LAS VEGAS (Reuters) - Gunfire erupted in the lobby of the medieval-themed Excalibur Hotel and Casino on the Las Vegas strip on Friday, killing two people in an apparent murder-suicide, Las Vegas media reported.

Police identified the dead as a woman who had worked as a concierge and a man who died from a self-inflicted wound, the Las Vegas Review-Journal newspaper reported. There was no immediate word on the nature of their relationship.

The shooting came the same day a gunman shot dead 20 school children at a suburban elementary school in Connecticut, ultimately killing at least 27 people including himself in the one of the worst incidents of its kind in U.S. history.

Several people who said they were staying at the castle-shaped Las Vegas hotel sent out messages on Twitter expressing their alarm.

"Someone started shooting inside Excalibur & I'm stuck in our dressing room waiting to see if it's safe to come out," tweeted Uraina Serna.

Calls to the Las Vegas police and the Excalibur were not immediately returned. But the hotel said on Twitter: "An isolated incident has occurred at Excalibur this evening, local authorities have the matter under control."

(Reporting by Timothy Pratt; Editing by Cynthia Johnston)