Iraqi security forces fanned out across Baghdad on Monday looking for three Americans who were reportedly kidnapped over the weekend, closing streets and conducting house-to-house searches.
An Iraqi intelligence official told the Associated Press news agency that the Americans had been kidnapped from their interpreter's home in the southern Baghdad neighbourhood of Dora.
The United States embassy said "several" Americans had gone missing in Iraq.
"We are working in full cooperation with Iraqi authorities to locate the missing Americans," said Scott Bolz, the US embassy spokesman.
Bolz did not identify the missing Americans or say what they were doing in Iraq.
John Kirby, a State Department spokesman, said that "due to privacy considerations" he had nothing further to add about the missing Americans.
"The safety and security of Americans abroad is our highest priority," Kirby said.
There were no immediate claims of responsibility for the abductions.
Search under way
According to witnesses, Iraqi security forces have set up checkpoints in the Dora neighbourhood southeast of Baghdad.
Two Iraqi army helicopters were also seen hovering over the district while police SUVs patrolled the streets.
The comments by US officials came after the Arab news channel al-Arabiya, citing its own sources, reported that three Americans had been kidnapped by militias in Baghdad.
Iraqi media reports said that the Americans went missing in the south of the capital on their way to Baghdad International Airport.
A Western security official, speaking on condition of anonymity because he was not authorised to brief the media, told AP on Sunday that he had been told three Americans went missing 24 to 48 hours ago.
Kidnappings in Iraq have been carried out by the Islamic State of Iraq and the Levant (ISIL) and Shia militias, as well as by criminal gangs demanding ransom payments, or disgruntled employees seeking to resolve workplace disputes.
The incident comes after a week that has seen a deterioration of security in and around the Iraqi capital after months of relative calm.
ISIL claimed a number of attacks in Baghdad and neighbouring Diyala province last week that killed more than 50 people, including an attack on a Baghdad mall. The string of ISIL attacks on civilian targets within areas of Iraqi government control follow battlefield losses, most recently in western Iraq.
Last month, Iraqi troops pushed fighters out of the centre of Ramadi, the provincial capital of Anbar province in Iraq's Sunni heartland.
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