Iran experts have said that the government hastily ordered the executions of Arash Rahmanipour and Mohammad-Reza Ali-Zamani, 37, another political prisoner, to intimidate the opposition and to silence the protests that have persisted since the disputed June 12 presidential elections.

With the government’s opponents planning another large demonstration on Feb. 11, the country is bracing for another wave of executions. At least nine other prisoners have been charged with the capital crime of moharebeh, which means waging war against God.

“The executions are clearly a sign of the government’s frustration to end the protests,” said Hadi Ghaemi, the executive director of the International Campaign for Human Rights in Iran, a group based in the United States. “There are fears that the government might engage in the kind of cleansing that it did between 1980 and 1988, when it executed more than 3,000 political prisoners.”

Nasrin Sotoodeh, Mr. Rahmanipour’s lawyer, said that the confessions had been extracted under duress, and that she had not been allowed to attend the trial.

Her client’s pregnant sister was arrested and held for more than two months, Ms. Sotoodeh said, to put pressure on Mr. Rahmanipour, and the woman ultimately had a miscarriage. And his father was handcuffed and carried away when he tried to attend the trial. He was told that his son needed to make confessions.