A British family of four, including two children, have been found stabbed to death in Gibraltar, local media reported on Monday.
The Royal Gibraltar Police have confirmed that a British male, 31 has been found stabbed to death along with a Spanish woman, 37.
Two girls, aged four years old and six weeks old have also been found stabbed to death.
Gibraltar police said they had ruled out natural causes but were not looking for anyone else involved.
"These are unexplained deaths but they are not of natural causes - we will have to wait until the postmortems are carried out," the Royal Gibraltar Police said during a press conference on Monday afternoon.
Police also confirmed that two UK Home Office pathologists would be flying out to Gibraltar tomorrow morning.
The incident has sent shockwaves throughout Gibraltar, with the government saying in a statement released on Monday:
"A peaceful society like the one we enjoy in Gibraltar will be hard-pressed to come to terms with such a horrendous tragedy."
Gibraltar's Chief Minister, Fabien Picard, said "As a husband and father, I - like no doubt all Gibraltarians and residents of Gibraltar - am in total shock to hear about this terrible crime."
The family, whose bodies were discovered in a rented flat, had only been in Gibraltar for a few days according to local media.
Detectives and forensic officers have reportedly been working in the flat in Boschetti's Steps since early on Monday morning and the area remains cordoned off, according to local media.
According to eye-witness reports quoted by the Gibraltar Broadcasting Corporation (GBC), at about 11am, a locally resident man was heard knocking loudly on his front door, as he called out to a visiting friend who had reportedly been staying with him.
When there was no response, the police was alerted and numerous police vehicles were soon parked at the scene.
A spokesman from The Royal Gibraltar Police told The Local they would not comment on the matter until their press conference, scheduled for 5pm.