Four members of Britain's Royal Navy have been accused of gang raping a woman at CFB Shearwater in Nova Scotia.

Speaking outside provincial court Friday, Crown attorney Scott Morrison said the sailors are alleged to have participated in a "group sexual assault" against the civilian woman in the barracks at the Halifax-area military base late on the evening of April 9 or early April 10.

He said the men, who were in Nova Scotia participating in a hockey tournament with local Armed Forces personnel, were arrested Thursday morning.

The Canadian Forces National Investigation Service (CFNIS) charged each man with one count of sexual assault causing bodily harm and one count of sexual assault committed with one or more other persons. The accused are:

Craig Stoner, 24, of Stonehouse.

Darren Smalley, 35, of Gosport.

Joshua Finbow, 23, of Stockbridge.

Simon Radford, 31, of Lower Gosport.

"This is a disturbing accusation of sexual assault," said Lt.-Col. Francis Bolduc, commanding officer of the CFNIS.

"I'm pleased with the full co-operation provided by the British authorities to support the hard work and diligence of the CFNIS team in responding to this matter."

The four men appeared in court in Dartmouth Friday afternoon to be charged. They are all being held in custody.

"Obviously the fact that they're British citizens adds a different complexity to dealing with bail, because we have to ensure that they will attend court to be dealt with according to the law. So that might slow down the bail negotiations," said Morrison.

"It's a sensitive issue and a very serious charge. At this point it's possible that they could be released, but the main issue is whether or not they will be allowed to leave Canada."

Capt. Kirsten Pilotte said the military police's entire 20-person detachment is working on the case.

The men will spend the weekend at the Central Nova Scotia Correctional Facility in Dartmouth.

"On Monday, they'll go before a judge for a show-cause hearing and at that point it will be determined whether or not they're going to receive bail and if so, the conditions of that bail," Pilotte said.

One of the four British Navy sailors charged with sexual assault. <a href="https://twitter.com/hashtag/cbcns?src=hash">#cbcns</a> <a href="https://t.co/cdU6wffF4f">https://t.co/cdU6wffF4f</a> —@Brett_CBC

Second of four British Navy sailors charged with sexual assault. <a href="https://twitter.com/hashtag/cbcns?src=hash">#cbcns</a> <a href="https://t.co/uUuqCL7W8I">https://t.co/uUuqCL7W8I</a> —@Brett_CBC

Third of four British Navy sailors charged with sexual assault. <a href="https://twitter.com/hashtag/cbcns?src=hash">#cbcns</a> <a href="https://t.co/fNisFnj1Se">https://t.co/fNisFnj1Se</a> —@Brett_CBC