A husband and wife from Britain were seriously wounded in a machete attack in Tobago, police said yesterday.
They said the attack on the Caribbean island was similar to one last year in which a Swedish couple were killed.
The victims were named as Peter Greene, 65, and his wife, Marion, 59, originally from Reading, Berkshire.
Police refused to provide details about the attack on Saturday afternoon. Tobago has been considered the safer part of the twin-island nation of Trinidad and Tobago.
Police superintendent Nadir Khan said: "It's a matter of serious concern. This is another serious attack on tourists."
The couple were airlifted to a regional medical centre in Trinidad, but authorities did not release details about their condition.
Mrs Greene was described as being in a serious but stable condition. Her husband was in a critical condition after being placed in a medically-induced coma to treat severe head injuries.
Deputy British Commissioner Jeff Patton described the attack as a "horrible crime".
The couple had been living in the town of Bacolet along Tobago's southern coast off and on for 10 years, it was reported.
Mr Khan said robbery has not been ruled out as a motive and said it was similar to the unsolved killing in October of Anna Sundsval, 62, and Oke Olsoon, 73, at their home in the Bon Accord area of Tobago, about seven miles from where Saturday's incident occurred.
Authorities detained a suspect in that case but released him for lack of evidence.
Tobago has registered eight murders this year, compared with four in 2008. The more industrialised island of Trinidad has had 321 homicides.