A Chinese court on Wednesday sentenced 10 pro-democracy activists who sought to flee Hong Kong by speedboat to between seven months and three years in prison, in a case with major political overtones for the territory.

The Yantian District Court in the southern city of Shenzhen gave the harshest sentence to one of the two accused organisers of the ill-fated Aug 23 attempt to reach self-ruled Taiwan. Relatives said all defendants pleaded guilty, a move apparently aimed at receiving lighter sentences.

The defendants are believed to have feared they would be prosecuted for their activities in support of Hong Kongs pro-democracy movement. Hong Kong media reports said at least one may have had a warrant out for his arrest under a tough new national security law imposed on the semi-autonomous territory by Beijing in June.

The court said it had held a private hearing for two underaged suspects and would not charge the them for illegally crossing the border even though they pleaded guilty.

Another organiser was given two years while other participants were given seven months in prison.

Relatives of the accused said they were prevented from hiring their own lawyers and that the charges are politically motivated.

The defendants could have been sentenced to up to a year in prison for crossing the border and seven years for organising the trip.

They were picked up after entering mainland Chinese waters for crossing the maritime border without permission.

While Hong Kong is part of China, travelers must still pass through immigration when going to and from the mainland, which surrounds Hong Kong by land and sea.