DEWSBURY remained on high alert today after the raids on homes in Thornhill Lees.
And police patrols have been stepped up to calm fears about retaliatory attacks.
Since London was targeted last Thursday mosques across the UK have been attacked. Now police and community leaders are appealing for calm after yesterday's shock news that at least three of the four bombers were from West Yorkshire.
West Yorkshire Police Chief Constable Colin Cramphorn urged people to remain "calm, resilient and measured".
"I know that the people of West Yorkshire will have increased concerns for themselves and their families," he said. "I also know that there are those who would seek to exploit those concerns. I urge the public to continue to be alert but not alarmed.
"I also urge them to reject any form of extreme response. They can be reassured that my officers are on patrol in greater numbers than usual and they will deal with any incidents that threaten the safety of the community.
"I ask that people continue to be calm, resilient and measured in what they say and how they act. We cannot afford to let those who seek to undermine our society succeed."
Terrorism expert Prof Paul Rogers, of Kirkburton, who works in the Peace Studies Department at Bradford University, has also appealed for calm.
"Because the people concerned come from within Britain there is a real risk to community relations," he said.