The US citizens, along with an Iraqi translator, were taken from a private Baghdad apartment by unknown gunmen, Iraqi security officials told reporters on Monday.

According to an anonymous official speaking with the AFP news agency, the men were taken to the "suspicious apartment" by the translator, where all four men were abducted. If true, the Americans would be the first kidnapped in Iraq since the US withdrew from that country in 2011.

The officials said they were currently searching for the men, whose names have not been released. It is also unclear as to when exactly the men went missing. Some Iraqi officials reported they were kidnapped on Sunday, the same day the US State Department confirmed their disappearance, while other reports have suggested they were kidnapped at an earlier date.

Possible links to Shiite militias

Baghdad has seen a rise in gangs carrying out killings and kidnapping.

The largely Sunni district of Dora where the men were reportedly taken has been known to be the target of Iran-backed Shiite militias. Qataris and Turks have been among those seized in recent months.

US officials said they were working closely with Iraqi authorities to locate the men. Security personnel in Baghdad had reportedly set up checkpoints in Dora, while helicopters were patrolling the skies above the city.

blc/kms (AFP, Reuters)