Deputy Metropolitan Police chief Pol Maj-General Piya Tawichai said that 14 people face prosecution for violation of the public assembly act, while three will be charged with violating maintenance of cleanliness and orderliness. 
The deputy chief said that police would check letters people had dropped in mock mail boxes, prepared by the rally organiser. 
At last Sunday's demonstration, the protest organisers had urged pro-democracy supporters to write letters to His Majesty the King. These letters were confiscated by police on Sunday evening, including the mock mail box. 
Piya said that the message in the letters would be checked, as it could be related to the violation of the public assembly act. 
Police also will investigate and prosecute those who damaged public buses that officials had used as barriers in the rally.

17 protesters face charges over alleged violation of law during Nov 8 rally

Some participants in a political rally last Sunday face prosecution in two cases -- violation of the public assembly act and the Act on maintenance of cleanliness and orderliness -- police said on Friday.