The experimental effort, which has not been disclosed, is being used to conduct mass surveillance of Palestinians in Gaza, according to military officials and others.

Within minutes of walking through an Israeli military checkpoint along Gaza’s central highway on Nov. 19, the Palestinian poet Mosab Abu Toha was asked to step out of the crowd. He put down his 3-year-old son, whom he was carrying, and sat in front of a military jeep.

Half an hour later, Mr. Abu Toha heard his name called. Then he was blindfolded and led away for interrogation.