A little-known Iraqi rebel group has said it kidnapped two Indonesian reporters who went missing near the central city of Ramadi on Tuesday.
Iraq is now the most dangerous posting for journalists
The Army of Warriors group released a video, showing the journalists - a man and a woman - holding up their passports and identification badges.
It said Indonesia must explain what the two were doing in Iraq, "otherwise their lives will be in danger".
The Indonesian president has appealed for the reporters' immediate release.
The missing pair were identified as female reporter Meutya Hafid, 26, and cameraman Budiyanto, 36 from Indonesia's Metro TV station.
In a separate development, a Swedish citizen held hostage in Iraq has appeared in a video, pleading for his life.
Minas Ibrahim al-Yussufi, a gun pointing at his head, appealed to the pope and Sweden's king to secure his release.
A group calling itself Martyr al-Isawy Brigades or "Iraqi Vengeance Battalion" has threatened to behead him.
The missing Indonesian reporters were believed to have been travelling in a rented car from Jordan to Baghdad.
The owner of the car told officials that they were stopped by an armed group near Ramadi.
In a video delivered to several media organisation on Friday, the Army of Warriors (Jaish al-Mujahideen) claimed it had carried out the attack.
The video showed a man and a woman holding Indonesian passports and Metro TV staff card with two masked men pointing guns at them.
"The mujahideen are now investigating the reason they are in the country... and we ask the Indonesian government to clarify their position regarding this," the video - broadcast by Arabic TV station al-Jazeera - said.
Indonesian President Susilo Bambang Yudhoyono later appeared on al-Jazeera to appeal for the reporters' safe release.
"The Indonesian journalists kidnapped in Iraq were on a professional assignment and they did no t intend any interference in Iraq's internal affairs," Mr Yudhoyono said.
"As the world's largest Muslim country, we are concerned about what is going on in Iraq and these journalists brought us news of Iraq."
The Iraq conflict has been deeply unpopular in mainly Muslim Indonesia, feeding suspicions that the war on terrorism is being used as a cover for an attack on Islam.
The town, 110km (70 miles) west of Baghdad, has frequently seen clashes between militants and US or Iraqi government forces.
Two Indonesian women taken hostage in Iraq last year were released after their abductors established that they were Muslims.
The journalists' disappearance comes two days after a video emerged of a captive Italian reporter pleading for help.
Giuliana Sgrena, who works for the Italian newspaper Il Manifesto, was seized by gunmen in Baghdad earlier this month.
In the video tape released, she calls for the US withdrawal and personally appeals to her husband to save her.
"Nobody should come to Iraq at this time," she says. "Not even journalists. Nobody."
A little-known militant group, Islamic Jihad Organisation, has said it kidnapped Mrs Sgrena and is demanding that Italy withdraw its troops from Iraq.
At least 13 foreigners are believed to remain in the hands of their captors.