A 29-year-old bus driver of Indian origin was charred to death on Friday while sitting behind the wheel in a shocking attack in Australia's Queensland state.
A 48-year-old man at the scene was arrested after he allegedly boarded the bus in Brisbane before "throwing some type of incendiary device at the driver", Manmeet Alisher, Xinhua news agency quoted police as saying.
The attack took place when Alisher, who was driving a Brisbane City Council bus, pulled into Moorvale Shopping Centre on Beaudesert Road to pick up more passengers.
In India, the Aam Aadmi Party (AAP) said Alisher was one of its volunteers in Australia and mourned his death.
"Manmeet Alisher, AAP volunteer from Australia, was murdered," tweeted AAP leader Durgesh Pathak. "We stand by his family in these tough times."
Alisher, also known as Manmeet Sharma, hailed from Sangrur in Punjab and had reportedly moved into Australia nine years ago. Sangrur is represented in the Lok Sabha by AAP's Bhagwant Mann.
Queensland Police Commissioner Ian Stewart said in Brisbane: "Sadly the driver died as a result of his injuries."
He said there was no evidence of any link to "terrorist type activities" or links to racial motivation.
"While we don't know the motivations at this stage, I want to reassure the community that we take these incidents very seriously," Stewart said, adding counter-terror authorities were initially involved.
Local media reported that Alisher was a popular Indian singer and a prominent figure in Brisbane's Punjabi community.
He was described as a soft spoken, courteous and genuine man.
Several passengers on board the bus at the time managed to escape via the rear doors "partly because of the heroic actions of a taxi driver who saw what was unfolding", Stewart said.
Six people were taken to hospital for smoke inhalation and minor injuries.
The Australian media reported that flags will be flown at half mast across Brisbane on Saturday.
Alisher's death was also mourned by AAP leaders Kumar Vishwas and Preeti Sharma Menon, both from the AAP Overseas Wing.
"Devastating news," Menon tweeted. "AAP volunteer killed in shocking attack. He will be missed."
Queensland has been in mourning over the past week following the deaths of four people in Australia's largest amusement park Dreamworld and the murder of a woman in Brisbane.