BANGKOK (REUTERS) - Authorities in Thailand's southeastern Chonburi province braced for more demonstrations on Wednesday (Nov 1) after hundreds of furious residents gathered a day earlier in a rare protest to complain about bureaucratic incompetence.

Residents complained about long lines that lasted more than 12 hours and general disorganisation surrounding activities to mark the funeral of late King Bhumibol Adulyadej, who was cremated in Bangkok last week in a US$90 million (S$122.46 million) funeral.

The protest defied a junta ban on gatherings of more than five people that has been in place since a May 2014 coup.

It is also rare because anything remotely related to the monarchy is a sensitive topic in Thailand - the royals are protected by a draconian lese-majeste law, which criminalises all perceived insults toward the monarchy.

The Chonburi protests, however, were directed at the local authorities and not at the palace.

Protesters in the sea-side province shouted "Get out!" on Tuesday as they demanded that provincial governor Pakarathon Tienchai step down over what they said was poor organisation of ceremonies to mark the funeral.

Many wore yellow, the king's colour.

There have been similar calls for the governor of Nonthaburi province, north of Bangkok, to step down. Some in Nonthaburi reported waiting for up to eight hours to lay flowers for the late king.

Chonburi Governor Pakarathon spoke to the crowd on Tuesday and denied his staff had mismanaged the event.

Prime Minister Prayuth Chan-o-cha on Tuesday urged Thais to forgive those involved in the organisation of the funeral and overlook any problems that arose.

"The number of people who took part in the funeral caused a few problems," he said.

Hundreds of thousands of people turned out to see King Bhumibol's funeral in Bangkok last week.

The late king, who ruled for more than seven decades, was seen as a father-figure.

For those unable to make the trip to Bangkok, 85 miniature replicas of the cremation pyre were arranged across Thailand.

Hundreds of other areas were designated as places for mourners to lay flowers.

"I waited 13 hours!" shouted one Chonburi protestor on Tuesday.

Similar stories have emerged around the country as netizens took to social media to vent their anger.

Some said the mismanagement exposed Thailand's jarring class divide.

Chonburi protesters said they were unhappy with the funeral's US$90 million budget.

The late king frequently spoke about self-sufficiency and was portrayed as a frugal man despite his own enormous wealth.

Others still argued that government officials were given preferential treatment when laying flowers.

"Officials went first before the public," Mr Tanarit Kumwivat, from the northern province of Chiang Mai, said in a Facebook post.

The Chonburi protest comes at the end of an epoch. King Bhumibol, who was also known as "the people's king", was a rare figure of unity in the politically divided nation and his death has left some Thais anxious about the future.