Authorities in West Java, Indonesia, have foiled an attempt to smuggle drugs into a jail.

On May 11, the police narcotics unit in Depok arrested four people over an alleged attempt to smuggle more than 2,000 crystal meth pills and four ecstasy tablets into the Cilodong Penitentiary, The Jakarta Post reported.

Depok police spokesperson First Inspector Made said the bust happened after a tip-off. They coordinated with prison guards and inspected all items brought into the facility by visitors.

One visitor was found with 100 crystal meth and four ecstasy tablets concealed in a packet of milk powder that was to be handed to a prisoner identified as F. The visitor admitted he had obtained the drugs from an unknown individual in West Jakarta that was introduced to him by F.

Three other locations were also raided, where police found more packages of crystal meth. Four suspects, including the visitor and F, were being questioned by authorities as they continue to investigate the case.