Tong Ying-kit, 24, had earlier pleaded not guilty to inciting secession and engaging in terrorist activities after allegedly riding a motorbike into a group of police officers while flying a flag with the protest slogan "Liberate Hong Kong, revolution of the times" last July 1.

He has been remanded in custody pending a 15-day trial, starting on June 23. The case will be heard by national security judges Anthea Pang Po-kam, Esther Toh Lye-ping and Wilson Chan Ka-shun without a jury.

The case was mentioned in the high court yesterday where the three national security judges gave instructions to the prosecution.

During the hearing, senior assistant director of public prosecutions Anthony Chau Tin-hang suggested there is no need for the prosecution to prove Tong caused or intended to cause grave harm to society. Chau said Tong could be convicted as long as they proved he committed one of the terrorist activities listed in the law, such as coercing the government.

But judge Chan said the scope of the security law would be too wide in that case. He cited an example of people cutting the electric wires of a room to coerce the government and questioned whether they would be convicted.

Judge Pang said all wounding cases could be regarded as violations of the security law if Chau's approach was adopted.

But the judges eventually decided the prosecution would not need to prove Tong had used force, because the security law states a person can be found guilty regardless of whether or not he uses force.

The judges required the prosecution to clearly list Tong's offenses in the opening statement and how the acts constituted incitement.They also asked the prosecution to provide the opening statement for the defense by May 30.

The Department of Justice earlier decided against using a jury for Tong's trial. Tong has filed a judicial review against that - the hearing has been scheduled for May 10.