U.S. troops continue to "tighten the noose" in their efforts to capture Saddam Hussein (search), a U.S. military commander said Friday.

Soldiers detained 13 people -- including as many as 10 believed to be part of Saddam's personal security team -- during a raid on a house south of Tikrit (search), Maj. Gen. Ray Odierno, commander of the 4th Infantry Division (search), said in a video-teleconference from Iraq with reporters at the Pentagon.

Tikrit is the former Iraqi dictator's hometown and a source of continuing support for his deposed regime.

The raid was based on intelligence from local Iraqis.

Asked whether he believed U.S. forces were closing in on Saddam, Odierno said it was unclear whether the newly captured members of his security detail had been protecting him recently.

• Map: Postwar Iraq

But he said information from Iraqis has been "flowing in" in the past 24 hours, and the military continues to gain more and more information about the ex-dictator's possible whereabouts.

Odierno said U.S. troops also have spoken with one of Saddam's wives. He did not identify her.

"We continue to tighten the noose," he said.

Odierno said officials are still sorting through the detainees. Asked if there were reports that Saddam himself was believed to be nearby, Odierno wouldn't talk about any specifics, but he said there are a number of operations following up on a number of leads.

Another raid Thursday led to the location of a former Baath (search) party member and a leader of the group "The Return," which has been trying to return the Baathists to power after the U.S.-led coalition ousted Saddam and toppled his regime. It's believed the man was partly responsible for leading attacks against U.S. troops since the war ended.

Also in the past 24 hours, Fox News has learned, an Iraqi nuclear researcher turned himself in to the U.S. military in Baghdad. Although it's not yet known just what information, if any, he is supplying, senior defense officials say this, too, is promising news.

The Bush administration and U.S. officials hope more Iraqis will come forward with information about the whereabouts of former regime members following the release of pictures and videos of the bodies of Saddam's sons Uday and Qusay, who were killed in a firefight with U.S. forces Tuesday.

Odierno said his troops have detained 1,000 individuals in the past 30 days alone and seized huge amounts of explosives, ammunition and weapons.

U.S. troops in Iraq have come under attack an average of 12 times per day since President Bush declared the end of the war.

But Odierno said attacks on U.S. forces in the area have dropped by half in the past month. Although there are fewer attacks, some have been more sophisticated, including the use of improvised bombs, Odierno said.

In Thursday night's raid in Tikrit, troops found a weapons cache including 45,000 sticks of dynamite and 11 assembled bombs.

Odierno said his 27,000 soldiers are preparing for the possibility of attacks with car bombs or homicide bombers. Anti-American forces also are increasingly shifting their attacks to Iraqis working with U.S. troops, he said.

"They are going after softer targets, because they know they're ineffective against military targets," he said. "We see this as a desperation move."

Attacking Iraqis is backfiring and prompting more citizens to offer the Americans helpful information, Odierno said.

He said the deaths of Saddam's sons haven't changed the number or type of attacks on his troops, but the killings have prompted more tips from Iraqis such as the ones that led to Saddam's bodyguards and the weapons cache.

"We've shown them no one of the old regime is going to survive," Odierno said.

Troops of the 4th Infantry Division have been told they probably will stay in Iraq for a year.

Fox News' Bret Baier and The Associated Press contributed to this report.