Their charges include riot, rioting injuring buildings and wilful damage. Additional charges of common assault were levelled against four men, Nauru government spokesman Rod Henshaw said.

All are being tried under Nauruan law, and the charges carry possible jail terms of up to seven years. Two of the group have voluntarily returned to Iran since the incident.

The group's last appearance on November 18 was an emotional one, with asylum seekers at first refusing to participate over concerns they would not get a fair trial. Then, the men had refused to leave their bus outside Nauru's tiny courthouse for two hours after being told they would be represented by a man they had not met, the island's public defender.

Local lawyer Pres-Nimes Ekwona agreed to represent the men at that hearing, and it is believed he represented the men again on Monday, although he warned he would be unable to represent all the defendants.

Four men were unable to appear in court for medical reasons, Mr Henshaw said.

The asylum seekers were not required to enter a plea, but it is expected they will be required to plead guilty or not guilty when they reappear on January 14.

■ Australia and Indonesia will sign an agreement on Tuesday to boost co-operation in search and rescue operations involving asylum seekers. The agreement, mooted after incidents in which hundreds of asylum seekers lost their lives, is expected to give Australian aircraft rapid clearance to enter Indonesian airspace and speed up the response times.

With AAP

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