A day after Spain's incoming prime minister said he plans to pull his country's troops out of Iraq, President Bush is urging other countries not to do the same. This, as two more foreigners working there are shot dead in what have been a series of deadly attacks against civilians.

Two Europeans, believed to be German and Dutch, and both working on a water project near the southern city of Karbala were shot dead Tuesday along with two Iraqis. They, along with four American missionaries killed a day earlier in Mosul, were all said to have been gunned down in drive by shootings.

We're grieving, we're in shock, we're heartbroken," said Eric Bridges, spokesman for the Southern Baptist International Mission Board, the Virginia-based group that sent the missionaries to Iraq to do humanitarian work. He believes those responsible for these killings as well as the recent shootings of other civilians are looking for targets of opportunity instead of going after better protected soldiers. "They're seeking foreigners who are out and about who are not protected, who have no security."

The recent attacks are also claiming the lives of Iraqis seen as supporting the U.S.-led occupation and appear to mark a trend by insurgents of targeting civilians instead of soldiers. Military analyst and retired U.S. Army Colonel Ken Allard said the attacks are designed with a clear message in mind. "It sends the signal that anybody that is there on the side of the U.S. or for that matter in the Iraqi population siding with the United States, cooperating or working with them is absolutely vulnerable to an attack," he said.

But as he met with the prime minister of the Netherlands, President Bush had a message of his own for countries that may be thinking about pulling out of Iraq, as Spain's incoming prime minister says his government will do, if the United Nations is not put in charge of the military operation there. "I would ask them to think about the Iraqi citizens who don't want people to withdraw because they want to be free," he said.

Last week, two American civilians working for the U.S. military in Iraq were gunned down along with their Iraqi translator. With targeted assassinations continuing to be a problem a year after the U.S.-led invasion, a majority of Iraqis asked in a new poll say a lack of security remains their number one concern. But a majority (56 percent) also say their lives are better today than they were before the war.