The court's decision, which was rescheduled from the morning to the afternoon Tuesday, drew strong support from the detainees' families and friends, the media, scholars -- particularly from the Nitirat jurist group, as well as representatives of 10 embassies.
The 13 activists were arrested on June 23 by Bang Sao Thong police as they were distributing leaflets on the draft charter referendum in Samut Prakan.
They were charged with violating the National Council for Peace and Order's (NCPO) ban on political gatherings of more than five people, and sedition.
The group included university students from the New Democracy Movement and labourers.
Six of them sought bail which was granted while seven, all students, engaged in civil disobedience against their arrest by not requesting bail.
Also on Tuesday, police sought court approval for the continued detention of all 13 suspects, including those who had already been already granted bail, for a further 12 days.
But the court rejected the request, saying that as the Military Court had said the investigators had already completed their probe, there was no need to detain them. However, prosecutors will continue with their case.