The government is trying to confirm claims by an armed Iraqi group that South Koreans are included among hostages that it has captured.

A Foreign Ministry official said Sunday that the ministry had instructed the South Korean Embassy in Iraq to confirm such claims made by the Brigade of Martyr Sheikh Yassin, a group which is hardly known.

The official added that Seoul is currently cooperating with Washington, Tokyo and other governments whose nationals are said to be held hostage by the group.

Earlier on Saturday, the Dubai-based Al-Arabiya television station reported that the armed group claimed that it is holding 30 hostages, including South Korans, and threatened to kill them unless U.S.-led forces pull out of Fallujah.

The report came a day after seven South Korean civilians were set free after being in captivity by armed Iraqi men for several hours.