Police and witnesses said they were seized from a hotel in the city of Basra by at least eight gunmen.

CBS released a statement saying the two were missing and that efforts were under way to find them.

The network did not name the journalists and it requested that others refrain from speculating on their identities.

"CBS News has been in touch with their families and asks that their privacy be respected," the statement added.

The journalists were taken from the Sultan Palace Hotel, police and witnesses said.

A member of staff was quoted as saying the gunmen had arrived at the hotel earlier in the day and inquired about who was staying there. They are said to have returned later in a four-wheel drive vehicle.

Other reports say the group were masked and carrying machine-guns.

Dangers for media

Iraqi Interior Ministry spokesman Abdul Karim Kallaf said police were searching for the journalists.

"As soon as we heard reports of their disappearance, the minister of the interior issued an order for the Iraqi police and intelligence service to be on high alert."

The disappearance of the journalists comes amid continuing concern about the dangers faced by media staff in Iraq. International media watchdogs report dozens of journalists killed each year since the US invasion of Iraq in 2003.

The New York-based Committee to Protect Journalists expressed concern at the fate of the two.

"Iraq is the most dangerous country in the world for journalists and the deadliest conflict for the press in recent history," it said.