Police found a dozen bodies trapped in a grate in the Tigris River, and a roadside bomb killed two U.S. soldiers on a foot patrol south of Baghdad Saturday as nearly 50 violent deaths were reported across Iraq.

Prime Minister Nouri al-Maliki banned a Kurdish extremist party from operating in Baghdad in a move seen largely as a gesture to Turkey, which had threatened to send troops across the border to destroy the group's bases in northern Iraq.

Also Saturday, a state commission said nearly 40 top officials of the past two governments have been ordered to appear in court to answer allegations of corruption. They include former ministers of defense, labor and electricity, the commission said.

The 12 bodies were found in Suwayrah, 25 miles south of Baghdad, at one of a series of metal grates fixed in the river to block debris, Mamoun al-Rubaie of the Kut city morgue said.

All were men between 35 and 45 years old and had been bound, blindfolded and shot in the head or chest, al-Rubaie said. They appeared to have been the victims of sectarian death squads that operate in the religiously mixed communities in the Baghdad area.

Police also found 15 other bullet-riddled bodies of men who had been handcuffed and blindfolded in six neighborhoods throughout the Baghdad area, police Lt. Mohammed Khayoun said.

Another 21 people were killed Saturday, mostly in Baghdad but also in Hillah, Mosul and Basra.

The roiling violence, especially between Sunni and Shiite Muslims in the Baghdad area, has alarmed U.S. commanders, prompting them to order nearly 12,000 more American and Iraqi soldiers into the capital.

The United States currently has about 32,400 troops in Baghdad and areas south of the capital — of which about 13,500 are in the city proper, Maj. Gen. James Thurman said Saturday.

U.S. and Iraqi officials have said the reinforcements will focus on about four neighborhoods where Sunni residents do not trust the Shiite-dominated Iraqi security forces.

Nevertheless, Gen. Peter Pace, chairman of the Joint Chiefs of Staff, said he would not rule out significant U.S. troop reductions this year. Pace, who arrived in Baghdad on Saturday, said such a decision would depend on improvements in the security situation and would come after consultations with U.S. commanders in Iraq.

As part of the renewed security crackdown, the U.S. military Saturday said that 60 men had been rounded up the day before at a funeral in the southern Arab Jabour neighborhood, a mostly Sunni district.

The 60 were believed to include members of an Al Qaeda-affiliated cell that "specializes in bomb making" and carried out car bomb attacks in the capital, a U.S. statement said. Women and children at the funeral were separated from the men and the arrests were made without incident, the statement said without giving any details.

"The group has been reported to be planning and conducting training for future attacks," it said. "Multiple forms of credible intelligence led the assault force to the location, later determined to be a funeral gathering, where the suspects were detained."

Late Saturday, Iraqi state television announced that 16 "terrorists" had been arrested for allegedly exploding a dozen car bombs in Baghdad and plotting to assassinate relatives of the prime minister in his hometown near Karbala.

The independent Commission for Public Integrity said the corruption allegations had been filed against 39 top officials in the governments of former prime ministers Ayad Allawi and Ibrahim al-Jaafari, according to the commission's spokesman, Ali Shabbout.

Shabbout said the officials include ex-Defense Minister Hazem Shaalan and former Labor Minister Laila Abdul Latif, both of whom served in the Allawi government, and Abdul Muhsin Shalash, the electricity minister under al-Jaafari.

Some have fled the country, but Abdul Latif was released on bail, Shabbout said.

In a brief statement, the government said al-Maliki had banned the Kurdistan Workers Party, a rebel group fighting for autonomy in southeastern Turkey, from operating in Baghdad. Al-Maliki told Turkish Prime Minister Recep Tayyip Erdogan of the order during a telephone conversation Saturday, the statement said.

It was unclear whether the order would have significant effect on the party, known by its acronym PKK, which is not known to have a major operation in Baghdad. The party has been fighting Turkish forces since 1984 and is considered a terrorist organization by Turkey, the United States and the European Union.

The PKK operates clandestine bases in the Kurdish-self ruled provinces of northern Iraq, where central government authority is limited.

Last month, Erdogan said Turkey was moving forward with plans to send troops into northern Iraq to attack PKK bases but was holding talks with the United States and Iraq in an attempt to defuse tensions.

In an interview with the New York Times published Saturday, the U.S. ambassador to Iraq, Zalmay Khalilzad, said Iran was encouraging Shiite militias to step up attacks on U.S. forces in retaliation for the Israeli assault on Hezbollah in Lebanon. The Shiite Hezbollah is backed by Iran.

Privately, some senior U.S. officials are skeptical the Iranian government is doing more than providing money to select Shiite groups. Others insist Iran is providing weapons and training to some Shiite factions.