We were driving along a road in the countryside . The sky was clear . A light appeared behind us, at 30 degrees from south-east horizon, seemed distant like a plane but had no white lights and red flashing aircraft , only a constant white light and was at a very fast speed. He crossed the sky from south- east to the west, and disappeared into the horizon , behind the mountain of Montserrat. The event lasted a few seconds , 3 or 4.