JAKARTA - An Islamic State in Iraq and Syria (ISIS) sympathiser carrying explosives around his waist was the only casualty of a failed suicide bombing outside a police post in the Indonesian province of Central Java late on Monday night (June 3).

The man - identified as 22-year-old Rofik Asharudin - sustained injuries to his stomach and hand, and was taken to a nearby hospital, national police spokesman Dedi Prasteyo told reporters on Tuesday.

He said seven police officers were at the post at the time of the blast but they were not harmed.

"Based on our investigation, the perpetrator was influenced by ISIS teachings," he said.

"He is now in a stable condition, and can communicate... We only interviewed him briefly, but once he is healed, we can find out more about how he was influenced by ISIS - whether it was through social media, or through contact with people."

Brigadier-General Dedi added that the attacker is thought to be a lone-wolf terrorist. There are no indications yet that he was working with a terror cell or network.

Officers searching the suspect's home have found, among other things, detonators and plastic containers of potassium chlorate. When combined with a fuel, the chemical can form an explosive material.

The blast took place at about 10.30pm on Monday - just two days ahead of Idul Fitri, or Hari Raya - outside a police shelter near a toll road exit in Kartasura, where officers were monitoring bustling traffic.

Millions of Indonesians are making their way home in an annual mass exodus, or mudik, for the Idul Fitri holidays, which come at the end of a month of fasting. Attacks during holiday periods are not uncommon.

On the eve of Idul Fitri in 2016, a suicide bomber attacked a police station in Solo, Central Java, killing himself and injuring an officer.

The year after, a policeman on sentry duty at the North Sumatra Police Headquarters was stabbed to death by two assailants in the wee hours of the first day of Idul Fitri.

A search of one of the perpetrators' homes uncovered an ISIS flag among his possessions.

In 2018, four men reportedly preparing for terror attacks during Ramadan and Idul Fitri were shot dead in West Java by counter-terrorism troops.

National Police chief Tito Karnavian had previously called on officers on duty during the long holiday period to remain vigilant to prevent terrorist attacks.

Brig-Gen Dedi said on Tuesday morning: "The police chief has instructed us to wear body armour when we are on duty. Unarmed officers are also accompanied by armed personnel the Police Mobile Brigade (Brimob) and the Indonesian military (TNI)."

The authorities have sought to reassure the public that there is no need for alarm amid the festivities. Central Java governor Ganjar Prabowo told local media: "People should remain calm. The authorities are handling this, and the bomber is in police custody."

About 158,000 personnel have been tasked with making sure the Idul Fitri exodus goes ahead smoothly, said Brig-Gen Dedi.

"The community does not need to worry when they head home to celebrate Idul Fitri," he said.