Trainee officers being briefed outside Caloocan city police
© Aaron Favila/APTrainee officers being briefed outside Caloocan city police station on Friday.
An entire city police force in the Philippines has been sacked after some of its members were suspected in the killings of three teenagers, with others seen on surveillance cameras robbing a house.

The 1,200-strong Caloocan city police force will be relieved in batches and replaced, said Manila's metropolitan police chief, Oscar Albayalde. The officers will do 45 days of retraining, after which those facing no charges can be reassigned to other stations.

The justice department has started an investigation based on a murder and torture allegation against four Caloocan police officers allegedly linked to the killing of the 17-year-old student Kian delos Santos during an anti-drug raid last month.

The parents of two other teenagers - Carl Angelo Arnaiz, 19, and Reynaldo de Guzman, 14 - have also filed murder, torture and planting of evidence complaints against two Caloocan officers.

Last week, CCTV footage emerged that purportedly showed 13 policemen robbing a house during an alleged drug raid.

The crackdown on drugs by the country's president, Rodrigo Duterte, which has left thousands of suspects dead, has come under renewed scrutiny after the killing of Delos Santos. Police described the teenager as a drug dealer who fired at officers during a raid, but his family and witnesses said the student was shot as he pleaded for his life.

Witnesses pointed to evidence, including security camera footage, which they said showed two police officers dragging Delos Santos away shortly before shots rang out and he was found shot in the head, holding a pistol with his left hand although he was right-handed. Police officers testified at a Senate hearing that Delos Santos was not the man seen being dragged in the video, although several witnesses doubted the police statement.

Delos Santos's death was followed by another outcry over the killing of Arnaiz, a former student at the University of the Philippines. Police said he was killed in an exchange of fire with police after robbing a taxi driver last month. A government forensic expert, however, said Arnaiz appeared to have been handcuffed, tortured and shot five times.

Arnaiz's parents say he went out with De Guzman to buy a snack on the night of 17 August but never returned. They found Arnaiz in a morgue 10 days later.

De Guzman's body was found floating in a creek in a city north of Manila last week. His head was wrapped with packing tape and he had 28 stab wounds to his body.