A special federal prosecutor on Monday sought the arrest of ex-President Luis Echeverria (search) and other former officials for their alleged involvement in the massacre of student protesters in 1968.

Prosecutor Ignacio Carrillo (search) also is seeking Echeverria's arrest for the alleged illegal detention of a leftist activist connected to the student movement of 1968, Echeverria's lawyer, Juan Velazquez, told The Associated Press.

Carrillo first sought Echeverria's arrest in July 2004, also for genocide, in connection with a separate student massacre in 1971. A court rejected that request two months ago, saying there was insufficient evidence.

Velazquez said he was confident the newest petition to detain the 83-year-old ex-leader would be rejected as well.

"It is exactly the same thing: the deaths of that day in 1968 were the result of a confrontation, not a state policy," the lawyer said.

Carrillo did not issue any public statements on his latest request.

Dozens of students and other civilians died on Oct. 2, 1968, when police and military officials opened fire on them during a government protest. Officials estimated that about 25 people died, while activists contend that as many as 350 were killed.

At the time, Echeverria was Mexico's interior secretary. He served as president from 1970 to 1976. Military reports reviewed by the special prosecutor show that 360 sharpshooters fired from buildings surrounding the Tlatelolco Plaza (search).

One of the apartments from which shots were fired belonged to a sister-in-law of Echeverria.

The charge of illegal detention stems from the disappearance of Hector Jaramillo (search), an activist in the student movement of 1968 who was never seen again after being detained by federal authorities in January 1969.

Velazquez said he did not know how many officials Carrillo wanted detained, but said they included both civilian and military officials. Mexican news media reported that he had asked for the arrest of 12 people, including Echeverria.

The office of the special prosecutor for past social and political movements was created by Fox in November 2001 to investigate past crimes.

In addition to the two student massacres, the office is investigating the disappearance of numerous presumed leftist guerrillas during Mexico's so-called "dirty war," in the 1970s and 1980s.