KUALA LUMPUR, Malaysia (AP) — Prosecutors have filed sedition charges against another four opposition politicians and activists who urged Malaysians to protest what they insist was a fraud-tainted victory by the ruling coalition in recent national elections.

Prosecutors also charged a student activist with sedition last week. All five spoke at a political forum earlier this month and criticized the government.

(READ MORE: Malaysia’s deep divides)

Government critics say the charges are intended to deter rallies aimed at pressuring electoral authorities to investigate claims of irregularities in the May 5 polls. Prime Minister Najib Razak’s administration has denied unfairly prosecuting the men, saying they flouted a decades-old law meant to preserve public stability.

The four pleaded not guilty to sedition Wednesday in a Kuala Lumpur district court. They face up to three years in prison if convicted.