ISTANBUL — A group of academics from universities in Istanbul are standing trial on charges of engaging in “terrorist propaganda” for signing a declaration calling for an end to hostilities against Kurdish rebels in Turkey’s southeast.

Individual trials against some 150 academics kicked off on Tuesday in various courts in Istanbul and were expected to last several months.

The defendants were among hundreds of academics who issued a declaration in January 2016 denouncing government operations against Kurdish militants in some cities in southeastern Turkey. The declaration triggered strong criticism from President Recep Tayyip Erdogan, prompting prosecutors to begin legal proceedings against them on charges of “propaganda” supporting the outlawed Kurdistan Workers’ Party, or PKK. Many of the academics lost their jobs.

Human Rights Watch says the trials violate free speech and academic freedom.