Memorial Day weekend certainly was not a holiday for U.S. forces in Iraq. A series of simultaneous operations throughout the country either wrapped up or kicked off Sunday and Monday, with thousands of troops clashing with insurgents from Baghdad to Haditha to Mosul.

In one incident, soldiers from 1st Brigade, 25th Infantry Division (Stryker Brigade Combat Team) battled insurgents who attacked them during a raid in northern Anbar province, officials said.

The soldiers, from 2nd Squadron, 14th Cavalry Regiment, were operating with Iraqi army forces at the time. “Several” insurgents were reported killed or captured.

In western Iraq, U.S. and Iraqi forces wrapped up Operation New Market, a five-day series of raids in and around the restive town of Haditha. Some 1,000 U.S. and Iraqi troops took part in the operation, which “was launched in response to increased anti-Iraqi activity observed during the weeks preceding,” a U.S. military statement read.

Troops in the area had “discovered a higher-than-normal frequency of roadside bombs” in the days before launching the assault. Some three-dozen insurgents and several weapons caches were seized the operation, which also saw at least two Marines killed in action.

U.S. officials have said the area is used by foreign fighters making their way into Iraq from the Syrian border. In the Rahwah and Karabilah districts, U.S. forces skirmished with suspected members of Abu Musab al-Zarqawi’s network. According to U.S. officials, many of the fighter were from outside Iraq, including at least three Saudi Arabians and one Moroccan killed in firefights.

Wire services contributed to this report.