A Thai woman accused of insulting the country’s late king has been forced to kneel before his portrait outside a police station on the island of Koh Samui as hundreds of people demanded an apology.

The woman’s arrest and public shaming on Sunday was the latest of several such incidents since King Bhumibol Adulyadej died last week after a 70-year reign,plunging Thailand into intense mourning.

Two police officers led 43-year-old Umaporn Sarasat to a picture of Bhumibol in front of Bophut police station on the tourist island, where she knelt and prayed, both on the way into the station and the way out.

The crowd, some of whom held aloft portraits of the revered monarch, jeered when she first appeared. A line of police officers linked arms to keep them from surging forward.

It is likely that Sarasat, a small business owner, who is alleged to have posted disrespectful comments online, will face charges of insulting the monarchy.

“We are going to proceed with the case as best we can,” the district police chief, Thewes Pleumsud, told the crowd. “I understand your feelings. You came here out of loyalty to His Majesty. Don’t worry, I give you my word.”

Authorities were urging calm after people posted comments on social media about those not wearing black and white clothing to mourn the revered monarch, with some arch-royalists reprimanding people in public. A government spokesman said some Thais could not afford mourning clothes and urged tolerance.

There have been reports of profiteering as demand for mourning clothes has soared since Bhumibol’s death on Thursday.

Tens of thousands of Thais have descended on the Grand Palace in Bangkok where Bhumibol’s body is being kept, and the government has declared a year of mourning.

Several foreign governments have warned citizens travelling in Thailand to avoid behaviour that could be interpreted as festive, disrespectful or disorderly. On Friday, police and soldiers on the Thai resort island of Phuket dispersed a mob seekingto confront a man they believed had insulted the king.

Video footage showed the crowd blocking the road outside a soy milk shop and waving placards with slogans such as “buffalo”, a slang word for stupidity.

Thailand has draconian lèse-majesté laws that impose stiff prison sentences for actions or writings regarded as derogatory toward the monarch or his family.

The operator of Thailand’s main cable TV network has blocked foreign news broadcasts deemed insensitive to the monarchy since Bhumibol’s death.