I have water marks on my painted bedroom walls from using plain water to clean, is it possible to remove?

My room mate moved out so I decided to clean the room, the paint is about 4 years old but still looks new. I took a sponge with plain water and used a paper towel to soak up the excess. I came back a few hours later and now have water marks. Is there a way to remove the stains, I don't want to repaint the room since the paint still looks great. By the way, the color of the wall is red. It's only 1 wall painted red, the other walls are standard off white.I have water marks on my painted bedroom walls from using plain water to clean, is it possible to remove?
if the other 2 answers don't work you can kilz the whole wall and repaintI have water marks on my painted bedroom walls from using plain water to clean, is it possible to remove?
You need to wash the whole wall. Any paint that is 4 years old has picked up a coating of grime from the air. Use warm water and a mild cleaner and do the whole wall.
Try scrubbing bubbles and a sponge. It does accumulate soap scum over a period of time. So this will have to be scrubbed and the bubbles will do all the work for you.