The government has instructed South Korean troops stationed in the southern Iraqi city of Nasiriyah to suspend all activities outside their barracks. The instruction comes amid worsening security conditions in the war-devastated country.

The Defense Ministry also ordered the troops of the Suhee and Jaema units to step up vigilance Wednesday by conducting thorough checks on people entering their compounds.

Meanwhile, at least 25 Iraqis were killed and some 50 injured after a U.S. F-16 fighter jet launched a missile at a mosque in the western city of Fallujah Thursday.

U.S. Marine Lt. Col. Brennan Byrne said American troops waged a six-hour battle around the Abdul-Aziz al-Samarrai mosque with militants. A Cobra helicopter fired a Hellfire missile at the base of the structure's minaret and the F-16 dropped a 500-pound bomb.

Since Sunday, more than 230 Iraqis, 34 Americans and two other coalition soldiers have been killed in intense fighting. The Iraqi casualty figure did not include those killed at the mosque. At least 630 U.S. service members have died since combat in Iraq began a year ago.