The Jamaican prime minister, Andrew Holness, said that the crackdown was being undertaken with the support of the tourism industry.
The US State Department's Jamaica travel advisory was posted on January 10.
The Foreign Office has now told all Brit tourists to stay in their hotels, warning of "intensive law enforcement activities in response to recent violence including shooting incidents".
Jamaica Constabulary's force police commissioner, George Quallo, told the Jamaica Information Service 335 murders were recorded in St James Parish in 2017, nearly twice as many as the other parishes.
The tourists were urged to follow the local advice including restrictions in selected areas, and exercise particular care if travelling at night.
About 200,000 British tourists holiday in the Montego Bay area every year.
The St James Parish area - which includes Montego Bay - already boasts a murder rate twice as high as any other in Jamaica, with 335 recorded a year ago.
Mr Holness said members of the security forces would be equipped with "extraordinary powers" to deal with the situation.
"The declaration of a State of Public Emergency does not mean the suspension of the rule of law".
"Now is the time, if you know where the guns are, please tell us; if you know where the criminals are, please tell us", he said. Rocky Meade, also appealed for support for the security forces. "The troops have been refreshed in their training of human rights and how to engage with citizens".
A state of emergency has been declared in Jamaica following a rise in murder and violent crime.
All persons driving in and out of the parish will be subject to a vehicle and personal search, the statement added.
In the most recent incident, a auto carrying three men and a child was sprayed with bullets in a drive-by shooting just yards from Sangster International Airport on Tuesday.