US soldiers from the 2nd Squadron, 2nd Stryker Cavalry Regiment secure area near Baghdad 14 Jan 2008 (file photo)

U.S. and Iraqi forces have killed four suspected terrorists and detained at least 18 others during operations in central Iraq Wednesday.

Tens of thousands of coalition soldiers are participating in operations in Iraq's northern provinces, part of a wider offensive launched earlier this month. 

The push, mostly in and around Mosul, was announced last week after a large blast killed up to 50 people.  The blast occurred in a building the U.S. military said had been used by al-Qaida in Iraq forces to store weapons and explosives.

In Baghdad, a spokesman for the Iraqi defense ministry today told reporters Iraq is determined to rid Mosul of al-Qaida in Iraq militants.  He said Iraqi and U.S. forces will fight side-by-side to see the mission through.

The spokesman gave no details of the number of troops that would be involved, or when the operation would begin.  But last week, Prime Minister Nuri al-Maliki promised a "decisive" battle against the militants.

Some information for this report was provided by AFP, AP and Reuters.