BANGKOK (Reuters) - A Thai appeals court has dropped royal insult charges against six people jailed for setting fire to portraits of Thai kings, it said, but they will still have to serve lengthy jail terms for damaging public property.

Thailand has tough lese-majeste laws, with those found guilty of defaming, insulting or threatening members of the royal family facing up to 15 years in jail, but there have been no fresh prosecutions this year in what one rights lawyer said “appears to be a new policy direction”.

The six, aged between 18 and 20, were arrested last year for setting fire to portraits of King Maha Vajiralongkorn and his father, the late King Bhumibol Adulyadej, at several spots around the northeastern province of Khon Kaen.

A court found them guilty of lese-majeste, arson damaging public property and organized crime.

One of the six was jailed for 11 and a half years, three received terms of seven years and eight months, while two got three years and four months.

The appeals court on Tuesday cut the jail terms slightly - nine years instead of 11 and a half; six years instead of seven years and eight months; and three years instead of three years and four months.

“They are happy not to be sentenced under Article 112 (lese-majeste) because they did not have any ill intention,” their lawyer, Pattana Saiyai, said.

He said earlier the six had been hired to burn the royal portraits. Two men were jailed in June in connection with this.

The military, which took control of the government in a May 2014 coup, has said it needs to crack down on critics of the monarchy for the sake of national security.

Since the coup, at least 94 people have been prosecuted for lese-majeste, but the Thai Lawyers for Human Rights Centre said there had been no such prosecutions this year.

Only 10 lese-majeste cases remained before the courts, Pawinee Chumsri, a lawyer for the Thai Lawyers for Human Rights Centre, said.

“Since the beginning of this year, the court has dropped Article 112 prosecutions and pursued other charges instead,” Pawinee told Reuters. “It appears to be a new policy direction.”

A source within the junta, formally known as the National Council for Peace and Order, said the government was “careful” with lese-majeste prosecutions because of accusations that it uses the royal defamation law for political purposes.

All lese-majeste complaints were now being carefully screened by a police committee before any prosecution, the source said.