The Mexican Supreme Court has delivered a setback to prosecutors seeking to bring a former president to trial on genocide charges in connection with the deaths of protesters in 1971.

The high court agreed Wednesday with a lower court ruling that a 30-year time limit on prosecuting such charges is still in effect. A 2002 law canceled the 30-year statute of limitations on genocide, but the five-member high court says it agrees the law is not retroactive.

The Supreme Court says it will still consider other requests by prosecutors to bring the case to trial.

Former President Luis Echeverria has been accused of directing an attack on a student demonstrators 34 years ago. Prosecutors say he ordered paramilitary forces to fire on the protesters, killing at least 11 people. Mr. Echeverria denies the charges.

Some information for this report provided by AP and Reuters.