A special police task force raided the Din Daeng flats in Bangkok, making many arrests, after a riot policeman on duty in the area was shot and seriously wounded on Wednesday night.
Pol L/Cpl Detwit Ledtenson was shot in the head about 10.43pm behind Din Daeng flat 1 on Chaturathit Road, also known as Soi Saeng Uthaithip, and rushed to Police General Hospital.
A special police task force entered the area shortly afterwards and searched flats into the early hours of the morning.
Reports said 13 people were held for questioning – seven aged under 13 years, another five aged under 18, and an employee of an independent media organisation.
Earlier on Wednesday night, another 28 protesters were detained during an anti-government rally in the Din Daeng area.
On Thursday morning, forensic police and a bomb disposal team inspected the Din Daeng flats and nearby area.
National police chief Pol Gen Suwat Jangyodsuk visited the area on Thursday, leading a team to inspect an apartment in Soi Chaturathit 2 in Din Daeng district.
He said 29 people were now being questioned at Din Daeng police station.
Media reports said parents had earlier arrived at the police station to pick up children who were among those detained.
Residents said there had been no violence in their soi before and they were now fearful of what may come. They asked that protesters not gather in the soi because it would greatly affect people living there.
Pol Maj Gen Nitithorn Jintakanon, deputy commissioner at the Metropolitan Police Bureau, said the national police chief was giving priority to the investigation.
He also said many weapons were seized during the search. Pol Gen Nitithorn said the investigation would continue and would be extended, with information from people being questioned.