The military took over on May 22 after the government of Prime Minister Yingluck Shinawatra had been weakened by months of protests that forced ministries to close for weeks on end, hurt business confidence and caused the economy to shrink.
The political turmoil pits the Bangkok-based royalist establishment dominated by the military, old-money families and the bureaucracy against supporters of former telecommunications mogul Thaksin Shinawatra, who is adored by the poor in the north and northeast.
Thaksin, who was ousted as premier in a 2006 coup, is the brother of Yingluck and was considered the real power behind her government. He has chosen to live in exile since fleeing a 2008 conviction for abuse of power.
Since the latest coup, the military has banned political gatherings of five or more people and protests that have taken place in Bangkok have been small and brief.
Deputy police chief Somyot Poompanmoung had told Reuters that 5,700 police and soldiers would be sent into central Bangkok on Sunday and rapid deployment units were ready to stop protests that might spring up elsewhere.
Some top-end malls in the Ratchaprasong area chose to close or have reduced opening hours and the operator of the Skytrain overhead rail network shut several stations in the central area. "It's a business centre and we need to protectively avoid any damage if authorities need to break up a gathering," Somyot said, adding mall owners could also find themselves in trouble with the authorities if protests took place on their premises.
In the morning, Ratchaprasong had been swarming with police and media but there was barely a protester to be seen.
The Central World mall opened four hours later than normal at 2 pm. By mid-afternoon there were only a handful of shoppers in the mall, parts of which were burnt to the ground in the mayhem after an army crackdown on pro-Thaksin "red shirt" protesters in 2010.