Anti-government protesters converged on three sites in Bangkok on Saturday afternoon, in defiance of an emergency decree and despite a government-ordered shutdown of nearly all mass rail transit in the capital.

Rally participants were asked to go to the location closest to them: the Lat Phrao interchange, Udom Suk BTS station or the Wong Wian Yai roundabout. The locations were confirmed in a tweet sent out by United Front of Thammasat and Demonstration (UFTD) at 3.08pm.

Within an hour, large groups of demonstrators had made their way to each of the venues, raising three-finger salutes along the way. The biggest group was seen at Lat Phrao, where about 2,000 people had gathered.

UFTD also said rallies were planned from 4pm to 6pm in 17 provinces.

All 40 stations on the BTS Skytrain system were shut down at 3pm and would remain closed until midnight, the operator announced on its Twitter account. It said the shutdown was “due to an emergency decree announced by the government”.

The 38-station MRT Blue Line was closed at 12.30pm and the closure of the Purple Line followed at 3.30.

Police also ordered the closure of all stations on the Airport Rail Link to Suvarnabhumi Airport and blocked access to Victory Monument and the Asok intersection. Both sites had been viewed as possible gathering places for demonstrators.

The moves were made in anticipation of a fourth consecutive day of protests in defiance of the emergency decree imposed this week. In social media posts earlier on Saturday, organisers asked participants to board mass-transit trains at 3pm to prepare for an activity beginning at 4pm. However, the destinations were not announced until the very last minute.

Activists are trying to stay one step ahead of the authorities, who have been making efforts to stop them. On Friday, police laid razor wire across the Ratchaprasong intersection, where a huge rally had taken place on Thursday night, in anticipation of another gathering. The protesters adjusted quickly, moving to the Pathumwan intersection, where police used water cannon to disperse a crowd of about 2,000.

The suspension of mass-transit services on Saturday drew harsh comments from many people who posted messages blaming the subway operator on its Facebook page.