Five bikers have been killed in eight days

Officers will introduce a zero tolerance approach throughout the summer and no motorcycling offences will be ignored.

Thousands of riders travelling from England arrived in north Wales over the weekend and police say they were spotted driving at "excessive speed".

On Sunday, three people were killed following two deaths on 16 and 20 March.

Sunday's motorcycle accidents 0950GMT - A5104 Llandegla, male biker killed 1220GMT - A494 Corwen, pillion passenger killed 1340GMT -Nant Gwynant near Beddgelert, male biker killed

Although officers have not yet determined whether these deaths were as a result of speeding, they have decided to get tough with offending drivers.

Since the introduction in 2001 of Arrive Alive - a police scheme to cut the number of casualties at accident black spots - officers have recorded a reduction in the number of motorists speeding.

However, motorcycle accidents are still happening regularly.

A North Wales Police spokesman said they were convinced that the only way to change attitudes was to introduce proactive enforcement.

Chief Inspector Mark Owen said the action was needed to protect all road users.

"What I and others witnessed on our roads can only be described as sheer madness," he said.

Deputy Chief Constable Bill Brereton: Bikers will be targeted

"Large numbers of motorcycles were being ridden at excessive speed.

"Motorcyclists were overtaking in contravention of solid white lines, often in the path of oncoming vehicles.

"What I saw was a totally unacceptable standard of riding by a large number of people."

North Wales Police Deputy Chief Constable Bill Brereton's daughter died in a motorcycle accident in May 2001.

Mr Brereton, who is himself a keen biker, said people coming to north Wales to cause havoc will not be tolerated.

"If you don't intend to ride safely and lawfully keep away from the roads of north Wales," he said.

Operation Focus - as the crackdown has been called - will begin on Saturday and continue throughout the summer.

Extra officers will be used to patrol routes.

Chief Insp Owen added: "Enough is enough, we have been tolerant, we have listened to bikers representatives but this situation cannot be allowed to continue.

"We will carry on being involved with providing training courses and engaging with the motorcycling community but from now on we have no choice but to take a much firmer line in relation to enforcement."