PORTLAND (AP) - Another 30 Oregon National Guard soldiers are being mobilized for duty in Iraq this week, replacing soldiers who have been killed or injured, a spokeswoman said Monday.

The 30 soldiers will join 700 troops from the Guard's 2nd Battalion, 162nd Infantry who have been in Iraq since April.

The battalion has been hit hard in Iraq, where five of its soldiers have been killed in action. Three died in a June 4 ambush that was the worst single loss for the Oregon National Guard since World War II.

Another 29 soldiers in the battalion have been injured, said Guard spokeswoman Kay Fristad. Some of those soldiers have returned to duty. Others are being treated for their wounds statewide and overseas.

The 30 soldiers who are being sent as replacements will be formally mobilized at a ceremony in Salem on Tuesday that Gov. Ted Kulongoski will attend. They will be sent to Fort Hood, Texas for two weeks of training before they are sent to Iraq, Fristad said.

Kulongoski recently authorized Oregon National Guard members to voluntarily extend their service beyond the usual 24-month limit, in exchange for bonus pay from the government. Guard members are being offered an extra $1,000 a month for agreeing to serve up to an additional 12 months in Iraq or Afghanistan.

But Kulongoski also has expressed concerns about the Pentagon's heavy use of National Guard troops in the Iraq war.

In a letter to the Defense Department, Kulongoski said the lengthening of National Guard deployment "is evidence that our nation's military is facing a significant staffing issue that must be addressed."

The governor also said many Guard families are struggling financially, and the state is less prepared to deal with wildfires and other natural disasters with so many Guard members assigned overseas.