1250 GMT March 19, 2018
Prison officers became aware of the escape while conducting a morning check of inmates at the Kerobokan penitentiary in Bali's capital, Denpasar, said Putu Ika Prabawa, an officer at Bali's Kuta Utara police station.
Prabawa said the four men were believed to have escaped through a 50-by-70-centimeter hole found in a wall that connects to a 15-meter-long water tunnel heading toward a main street.
He identified the four as Shaun Edward Davidson, 33, of Australia; Dimitar Nikolov Iliev, 43, of Bulgaria; Sayed Mohammed Said, 31, of India; and Tee Koko King bin Tee Kim Sai, 50, of Malaysia.
Davidson was serving a one-year sentence for an immigration offense, while Iliev was serving a seven-year sentence for money laundering and another offense. Said and King were serving 14 and seven years, respectively, for drug offenses.
Prabawa said police have distributed pictures of the inmates who have escaped to police stations across Bali.
Jailbreaks are common in Indonesia, where overcrowding has become a problem in prisons that are struggling to cope with poor funding and an influx of people arrested in a war on drugs. Most prisoners have been convicted on drug charges.
Last week, dozens of inmates escaped from an overcrowded prison in western Indonesia after floods caused a wall to collapse.
Last month, more than 440 prisoners escaped from an overcrowded prison on Sumatra Island when they were let out of their cells to take part in Friday Muslim prayers.
In July 2013, about 240 prisoners, including several convicted terrorists, escaped during a deadly riot at a prison in Medan, the capital of North Sumatra Province.