US authorities say the 22-year-old sister of a gunman who committed a mass shooting in Ohio was one of those killed.

Police have named the shooter as 24-year-old Connor Betts.

9 people were killed in Dayton less than 24-hours after an earlier shooting in El Paso, Texas, where 20 people died.

The Mayor of Dayton, Nan Whaley - says US gun control laws need to be looked at again.

District Attorney Jaime Esparza for El Paso says they're working on a case against one suspect there.