A man armed with a pistol walked into an Oklahoma City restaurant at the dinner hour Thursday and opened fire, wounding two customers, before being shot dead by a handgun-carrying civilian in the parking lot, police said.

The shooting happened about 6:30 p.m. at Louie's On The Lake, a restaurant on Lake Hefner in the Oklahoma capital.

A woman and a female juvenile were undergoing surgery for gunshot wounds but apparently "are going to survive," said Capt. Bo Matthews, a police spokesman. A man suffered a broken arm while trying to escape the shooting.

A family member told KOCO-TV that her daughter and 12-year-old granddaughter were shot while entering the restaurant for the girl's birthday dinner. Authorities have not identified the injured patrons.

The suspect's identity also was not immediately known, Matthews said. The shooting appeared to be a random act.

"We have no reason to believe this is a terrorist type of incident," Matthews said. The motive was unclear otherwise, and the onsite investigation was expected to extend into the early morning hours as law enforcement personnel interview about 100 eyewitnesses, he said.

In April, a restaurant patron wrestled an assault-style rifle away from a gunman at a Waffle House in Nashville, Tennessee. Four people were killed in that shooting. Police have said there would have been far more casualties if it weren't for the patron's quick thinking.