Iraqi and U.S. military forces failed to find more than 100 Shi'ites reported to be held hostage in a town south of Baghdad.
The alleged hostage crisis erupted Sunday when some Iraqi officials said Sunnis in Madaen were holding the Shi'ites hostage and threatening to kill them. But a raid and search of the town turned up no evidence of the abductions.
Western journalists in Madaen and surrounding areas said the town was largely deserted when troops poured into it. Some residents and officials said initial accounts of the situation were greatly exaggerated.
Late Monday, gunmen killed a senior Defense Ministry advisor in Baghdad. Iraqi officials initially identified the victim wrongly as another defense official.