Hostage standoff ends in Portland

PORTLAND, Oregon (CNN) -- A seven-hour hostage standoff between police and a man holed up in an apartment with five children ended late Thursday with the release of the last of the children and the man's surrender, Portland police said.

Police fired two tear gas cannisters into the apartment after the last child was released, and moments later brought the man, identified as 34-year-old Ron Studer, out of the apartment.

Portland police spokesman Sgt. Brian Schmautz said it was unclear if all five children were biologically Studer's, and that the mother had been involved in the situation as it began at about 4 p.m. PDT (7 p.m. EDT).

"She was there at the time the original call came out but she was able to flee the apartment," he said.

Police said that Struder had threatened to kill the mother and the children.

Studer released two of the children at about 6 p.m., and two more about two hours later. The last child was released minutes after that. All five were in good condition, police said.

The five children were believed to range in age from one to 8 years old, said Schmautz.

Police responded to the initial 911 call on the standoff by sending more than a dozen police cars, an ambulance and a SWAT team to the apartment complex, cordoning off the area. Local television broadcast pictures of an armored SWAT vehicle accompanied by armed police dressed in camouflage uniforms.