At least 50 people have been kidnapped by unidentified gunmen in central Baghdad, Iraqi security officials say.
Travel agency staff and clients are said to have been targeted
The incident took place on Salihiya street, which is lined with transport firms offering travel around the country and to Jordan and Syria.
The gunmen arrived in up to 13 cars, and were wearing Iraqi special security forces uniforms, police sources said.
An interior ministry official later strongly denied some reports that the raid was officially sanctioned.
No-one has yet admitted carrying out the attack.
In a separate development, a court in Baghdad sentenced Mustafa Salman al-Jubouri, an Iraqi national, to life in jail after convicting him of involvement in the kidnap and killing of British aid worker Margaret Hassan in 2004.
Two other defendants were acquitted.
The gunmen in special police uniforms carried out the raid in central Baghdad in broad daylight, police and interior ministry sources said.
The victims are said to be mainly staff and customers of travel firms.
Passers-by and a street vendor were also rounded up in the raid, according to witness Haidar Mohammed Eleibi, who works for the Swan Transportation Company in Salihiya.
"They took all the workers from the companies and nearby shops," he told the Associated Press news agency.
"They did not give any reason for it. Police came afterwards and did nothing," he said.
Among those seized were two Syrian nationals.
The commander of the police commandos in Baghdad denied earlier reports that the raid was officially sanctioned.
"The ministry of the interior has nothing to do with this arrest and especially not the commando forces and the forces of public order brigades who are not authorised to do such operations," Maj Gen Rashid Fulayah told the AFP news agency.
The BBC's Ian Pannell in Baghdad says the situation is still confused but adds that this kind of kidnapping does happen quite frequently in the country.
Iraqis working on projects linked to the government or coalition forces are particular targets for abduction.
Other abductions are motivated by sectarianism or for money.