Leaders of an anti-government movement that staged a demonstration in front of the German embassy in Bangkok in October met investigators at Thung Maha Mek station on Thursday.
One of them said the anti-government protest has had to stop for a while due to the pandemic.
A total of 13 leaders met public prosecutors over their alleged violations of Section 112 of the Criminal Code (the lese majeste law) and Section 116 of the Criminal Code.
More than 10 policemen provided security in front of the station and plainclothes officers took photos of people who turned up to give moral support to the protest leaders.
The Oct 26 protest in front of the German embassy on Sathon Road was organised by the pro-democracy Khana Ratsadorn group, whose leaders deny all charges against them.
One of them, Patsaravalee Tanakitvibulpon, said they were waiting for the prosecutors to decide whether to charge them.
Ms Patsaravalee and the other protest leaders are facing a string of charges in a number of cases.
She said the latest summons against her had been issued two months after an earlier protest, on Oct 14.
Ms Patsaravalee admitted the new wave of Covid-19 infections in the country had made it harder for the protesters to gather but insisted they would rally again in the future.
Atthapol Buaphat, another protest leader, said the group also submitted more handwritten evidence and called on the police to question more witnesses.