Security has been tightened in Rangoon ahead of Wednesday’s Martyrs’ Day ceremonies, held annually to honor the assassination of independent Burma’s founders on July 19, 1947.

The government mouthpiece The New Light of Myanmar warned last week that “those who took part in the ’88 unrest and members of a political party” were “plotting to destabilize the country…by using Martyrs’ Day.”

The National League for Democracy confirmed Tuesday that it will hold a ceremony at its Rangoon headquarters on Wednesday and political activists led by former student leader Min Ko Naing planned a “peaceful march” to the tombs of the nine assassinated leaders, who included Burma’s independence hero Aung San.

Naing Aung, secretary general of the Thailand-based political coalition Forum for Democracy in Burma, said Tuesday there was a risk the authorities would launch attacks on the activists. “We are gravely concerned that the political activists are in potential danger of being labeled as destructive elements,” he said.

Rangoon residents said security forces had taken up positions around the NLD headquarters and at the Martyrs’ Mausoleum, which lies in the shadow of the golden Shwedagon pagoda. An official ceremony at the mausoleum is usually presided over by Burma’s culture minister, in the company of Burmese and foreign dignitaries and families of the nine assassinated comrades.

Veteran politician Amyotharyei Win Naing told The Irrawaddy on Tuesday that the Aung San family would probably be represented at Wednesday’s mausoleum ceremony by Aung San’s son Aung San Oo, the elder brother of opposition leader Aung San Suu Kyi, who is under house arrest and unable to leave her home. The last time she attended Martyrs’ Day ceremony honoring her father and his eight comrades was in 2002, shortly after she was released from her second term of house arrest.