Jakarta – Trials for about 30 people charged with involvement in riots in Indonesia's Central Java last week have already begun.

"The court has already begun their trials on Thursday and Saturday," said police chief Triyono from Pekalongan, 300 kilometres from Jakarta, where 1,000 people rioted for three days last week.

He said 12 suspects were tried on Thursday and a further 18 on Saturday on charges of damaging property and disturbing public order, but declined to give details. Officials of the court could not be reached for comment on Sunday.

Four people were still in hospital on Sunday after the riots from Monday to Wednesday.

A mob of 1,000 people vandalised more than 60 buildings, mostly shops owned by ethnic Chinese, and burned two trucks in Pekalongan on Wednesday.

The riots were preceded by the burning of an open air stage prepared for a pop concert organised by the ruling Golkar party that was to feature pop star Rhoma Irama.

The singer recently crossed over to Golkar from the Muslim-based United Development Party (PPP). - AFP