WASHINGTON (Reuters) - A gunman in central Dayton, Ohio, killed nine people including his sister and wounded 27 others in the second fatal shooting incident in the United States in less than a day, police said on Sunday.

According to the authorities, the first police response occurred one minute after the attack began, and was from a nearby police patrol arrived at the scene and dealt with the shooter and killed him.

Assistant police chief Matt Carper said the gunman was Connor Bates, 24, adding that the sister of the perpetrator Megan Bates, 22, was among the dead.

He said the attack began at 1 am local time in the historic Oregon area, which is famous for nightclubs, bars, art galleries and shops. The motive behind the shooting was not immediately clear, and investigators believe the gunman acted on his own.

Ten people, including the attacker, were killed and 27 others were wounded, five of them seriously, health authorities said.

The Dayton disaster, which is home to about 140,000 people and is located southwest of Ohio, is only 13 hours after a similar random killing at a Wal-Mart store in El Paso, Texas, on Saturday, killing 20 people and injuring 26 others. El Paso police arrested the bomber, a 21-year-old man.

The incidents are seven days after a teenager killed three people with an assault rifle at a California festival before committing suicide.