PARIS - French authorities have charged three people in connection with an attack in April on a Tunisian synagogue on the island of Djerba that killed 19 tourists, one of them French.

The three had been among a group of eight detained this month in Lyon. On Tuesday, France's top terrorism judge, Jean-Louis Bruguiere, charged one of the men, Walid Nawar, 22, with complicity to commit murder and attempted murder. Nawar is the brother of Nizar Nawar, who was killed in the attack when he apparently ignited a truck filled with propane outside the synagogue. The other two men, who were charged with "complicity in terrorist activity," were identified as Muhammad Fethi Nawar, Walid Nawar's uncle, and Tarek Hdia.

The police said Walid Nawar had bought a satellite telephone for his brother that was used a few hours before the synagogue attack to make a call from Tunisia to Pakistan to Khalid Shaikh Mohammed, who is thought to be al-Qaida's chief of operations. The cell phone had also been used to call Mohammed from France not long before the attack, the police said. They said they were able to trace those calls and others made to Spain before the attack.

In another case, a Muslim clergyman and two other members of his mosque in a Paris suburb were released yesterday after being detained for questioning in connection with unspecified terrorist activities, police officials said.