BAGHDAD (AP) -- U.S. authorities freed 500 Iraqi prisoners Thursday in an ongoing push to empty American jails of detainees no longer deemed a threat. But the military says it's still holding 25,800 Iraqis waiting to face charges or be given freedom.

The latest release provided only small relief to a detention system strained to the limit by about 17,000 new suspects captured this year in campaigns to secure Baghdad and its surrounding belts, the military said. U.S. officials worry the overcrowded detention camps are sapping resources and will overwhelm Iraq's struggling justice system.
The periodic releases are seen as both a symbolic gesture to highlight increased security and a needed safety valve. About 6,300 detainees have been released since January.
The ceremony — held behind concrete blast walls at Camp Victory, a sprawling U.S. base that contains several of Saddam Hussein's former palaces — coincided with other signs of progress in regaining control of former extremist strongholds since the arrival of 30,000 additional U.S. troops earlier this year.
Both U.S. troops deaths and civilian casualties have dropped in recent months. U.S. forces, meanwhile, have made important alliances with Sunni clan leaders to battle extremists such as al-Qaeda in Iraq.
But Sunni leaders also complain members of their sect make up the vast majority in both U.S. and Iraqi custody.
Flanked by U.S. soldiers, Prime Minister Nouri al-Maliki addressed the detainees, many wearing identical plaid shirts. ""Dear brothers, let's cooperate to shut down these prisons and write a new page of laws with the power of justice,"" al-Maliki told the men, who sat in rows of white plastic chairs under the Baghdad sun.
The backgrounds of the prisoners, including any suspected militant links, were not announced. The military issued a press release saying only that the detainees are ""no longer an imperative threat to Iraqi/coalition forces and the security of Iraq.""
One of the men, who identified himself as Jumaa Khashan, a Sunni from Ramadi, said he was arrested in 2005 on his way to visit relatives in the neighboring town of Khalidiya.
""At first, the treatment was bad ... but this year the treatment became better,"" Khashan said. ""I hope that Iraqis will renounce violence and work together to build a new Iraq.""
Another Sunni detainee also from Anbar province, Adel Khalaf, said he plans to return to Fallujah to look for his family.
""I will go back to see what happened to them. I haven't heard anything from them for the past 11 months,"" Khalaf said. ""The second thing I'll do is try to live a normal life.""