Police in northwestern England are questioning three men arrested in a counter-terrorist operation.

Lancashire police said on Saturday that they also were searching five houses in Burnley, about 200 miles northwest of London.

Police say they initially arrested nine men on Friday night as they were traveling on a major highway. Six of the men were released without charge.

The police say the operation was part of a continuing intelligence-led investigation by Lancashire Constabulary and the North West Counter Terrorism Unit. They declined to say what the three men were suspected of doing.