Iraqi Shi'ite politicians have criticized the United States for a U.S.-Iraqi military operation in Baghdad Sunday that left at least 16 people dead.

Monday, they accused U.S. forces of attacking a Shi'ite mosque near the capital's Sadr City neighborhood and killing unarmed worshippers. Iraqi President Jalal Talabani, a Kurd, called for an investigation into the incident.

But U.S. Lieutenant General Peter Chiarelli said someone went in after the raid and altered the scene. He said the Iraqi forces working with the Americans told them the site was not a mosque.

Coalition forces say Iraqi special forces, acting with U.S. advisors, killed insurgents and freed an Iraqi who had been taken hostage.

Separately, Iraqi officials say a suicide bomber killed 40 Iraqis at a joint U.S.-Iraqi base north of Baghdad.

Also Monday, unidentified gunmen kidnapped 16 employees of an Import Export company in Baghdad.

In other news, the Arab television network al-Jazeera aired a videotape purportedly from Saddam Hussein's fugitive lieutenant, Izzat Ibrahim al-Douri, calling on Arab leaders to boycott the Iraq government and support the Sunni-backed insurgency.

Some information for this report was provided by AFP, AP and Reuters.