Eight teenagers were arrested after a stand-off between police and up to 100 youths in Ellesmere Port, Cheshire.
The group walked around the Yeoman Way area of Great Sutton hurling bricks, stones and eggs at police cars for about four hours on Sunday night.
Officers shepherded the group away from children who were trick or treating in the area, occasionally entering the crowd to make arrests.
The force believes they deliberately sought a confrontation with police.
Police received a number of calls about eggs and other items being thrown at vehicles by a group of youths, some wearing Halloween masks, at about 1800 GMT on Sunday.
As well as throwing bricks, members of the group shone laser pens into the faces of officers who left their vehicles to make arrests or break up the group.
In the ensuing four hours police arrested eight teenagers, who were all detained overnight, and recovered a knuckle duster.
"This was a nasty example of public disorder, which seemed to be organized to set up a confrontation with the police," said Sgt Andrew Paine, of Cheshire Police.
"We dealt with it very firmly and the people involved will face the consequences.
"Anyone who is thinking of indulging in similar activity during the next few days, particularly on bonfire night, should take a lesson from that." Source: BeeBeeSee
String em all up...