About 4,000 to 5,000 Spaniards demonstrated on Sunday in the southwestern city of Seville in protest of an upcoming meeting of the North Atlantic Treaty Organization (NATO), police told local media.

The protesters, organized by the Seville Social Forum, marched around the historic center of the city and rallied outside the Andalusia Parliament.

They demanded the removal of U.S. military bases from Spain and the withdrawal of Spanish forces from such countries as Afghanistan, where NATO is engaging in military operations, said Jesus Lara, a spokesman for the Forum.

The slogan of the march was "NATO no, they will not pass," he said.

A second march with the same aim is scheduled for Feb. 8, the same day of the opening of the NATO meeting which will gather 26 ministers from NATO member states in Seville.

Forum officials said they will conduct a series of protests in the rest of the year to block NATO's following activities in 2007, describing the alliance as "the military wing of globalization" and "the protector of western powers and multinational companies."

Spain has about 600 soldiers in Afghanistan as part of NATO's military deployment in the Asian country.