JERUSALEM

Israeli prison authorities have placed the longest-serving Palestinian prisoner Nael Barghouthi in solitary confinement, said the Palestinian Prisoners Society on Monday.

"The Israeli prison authorities placed prisoner Nael Barghouthi, 62, in solitary confinement in Eshel Prison, it also threatened him to transfer him to another prison," the Palestinian NGO said in a statement.

The statement said that Israeli prison authorities claimed that Barghouthi made some remarks on his 40th year in jail, due to which, the prison service decided to put him in solitary confinement.

Nael Barghouthi is the longest-serving Palestinian prisoner in Israeli jails, where he had spent 33 years before he was released in the prisoner exchange deal between Hamas and Israel in October 2011.

Later, the Israeli forces rearrested him in June 2014, along with tens of other Palestinian prisoners who were released in the prisoner exchange deal, reinstating his sentence of life imprisonment and 18 years.

According to Palestinian figures, roughly 5,700 Palestinians -- including a large number of women and children -- are languishing in Israeli detention facilities.

*Ahmed Asmar contributed to this report from Ankara