By Aubrey Belford and Pairat Temphairojana
BANGKOK (Reuters) - Thai military courts on Friday jailed two people, one for 30 years and the other for 28 years, for insulting the monarchy, the heaviest sentences for the crime in the country's history, lawyers and a legal monitoring group said.
Thailand's lese-majeste laws are the world's harshest and make it a crime to defame, insult or threaten the monarchy.
The punishments come at a time of heightened anxiety over the health of the revered King Bhumibol Adulyadej, 87. The world's longest-reigning monarch, Bhumibol has been in hospital since being admitted for a check up on May 31.
Nervousness over the succession has formed the backdrop to a decade of political crisis in Thailand as former prime minister Thaksin Shinawatra and his allies have vied for political power with the establishment, dominated by the royalist military.
Friday's sentences are the latest in a surge in prosecutions and jail time for 'lese majeste' offences since Thailand's military took power in a May 2014 coup.
Military courts try most cases, in a junta-led crackdown that rights groups call an assault on free speech.
Pongsak Sriboonpeng, 48, was initially given a sentence of 60 years for six Facebook posts between 2013 and 2014, his lawyer, Sasinan Thamnithinan, said.
But the time was halved because he pleaded guilty, Sasinan told Reuters.
Pongsak, a self-described "red shirt" supporter of exiled former Prime Minister Thaksin Shinawatra, was shackled on his hands and feet for the hearing in a Bangkok courtroom that lasted less than an hour and was closed to the media.
Military prosecutors and court officials declined to comment on Pongsak's case.
In the northern city of Chiang Mai, another military court halved a jail term of 56 years for a 29-year-old woman, Sasivimol, who pleaded guilty, said Yingcheep Atchanont, a researcher at legal monitoring group iLaw.
The woman, who wanted only her first name used, was convicted for seven Facebook posts that insulted the royals, Yingcheep told Reuters.
"As far as we have recorded, these are the heaviest sentences for lese majeste in history," he said.
Since the 2014 coup, authorities have charged at least 51 people with lese majeste, including 24 convictions, a sharp rise over previous years, iLaw data shows.
Military courts usually give offenders up to 10 years on each count, double the figure before the coup, Yingcheep said.
The jump in cases was part of a general push for tougher enforcement, said Major General Weerachon Sukhondhapatipak, a government spokesman.
"We are applying nothing new in terms of law enforcement," Weerachon told Reuters. "It's just a matter of the previous administration neglecting to enforce the law properly."
(Editing by John Chalmers and Clarence Fernandez)