Islamist militant prisoners at a high-security jail in Indonesia have killed five police and were holding one hostage following clashes on Wednesday at a high-security jail on the outskirts of the capital, Jakarta, police said.
An inmate had also been killed at the jail in the Mobile Police Brigade (Brimob) headquarters in Depok, National police spokesman Muhammad Iqbal told reporters.
"Five of our colleagues died.... one of our colleagues is still inside and being held hostage," Iqbal said, adding that inmates were suspected to have taken weapons from the officers.
In a message carried on its Amaq news agency, Islamic State claimed responsibility for the incident and said that 10 counter-terrorism officers had been killed.
Iqbal denied that Islamic State was behind the attack or that it had been planned.
The police spokesman said a dispute had broken out with prisoners who objected to authorities making checks on food being brought into them.
He said police were still negotiating with the prisoners. "We are securing the situation, containing inmates so this doesn't spread. We are still negotiating so that we don't have to go to the last resort," he said.
Five ambulances had left the jail and arrived at a police hospital, where six orange body bags were placed on stretchers, according to Detik.com, an independent news website.
The head of the police hospital did not immediately respond to a request for comment.
Police officers maintained tight security around the jail on Wednesday and kept onlookers away from the entrance.
Last week anti-terrorism police arrested three militants suspected of planning an attack on three other police buildings in West Java.
Islamic State sympathizers have carried out a series of mostly low-level attacks in Indonesia over the past few years.
Last year, an attack by two suicide bombers, using pressure cookers packed with explosives, killed three police officers and wounded 12 at a Jakarta bus terminal.
In January 2016, four Islamic State-linked militants mounted a gun-and-bomb attack at a busy intersection outside a Starbucks cafe in central Jakarta, killing themselves and four others.