Mexican President Enrique Pena Nieto's plan to crack down on gang-linked police is drawing scorn among critics who say he recycled old ideas to address protests over corruption and impunity.

In crisis-mode over the presumed massacre of 43 students by a police-protected gang, Pena Nieto unveiled a raft of measures Thursday to get rid of the country's crooked municipal forces.

The constitutional reforms, which Congress must approve, would also give the federal government the authority to take over municipalities that have been infiltrated by drug cartels.

Presidential aides said the plan is similar to what Italy did in the 1990s to clean up mafia-infiltrated cities.

But analysts and critics say previous governments have toyed with similar ideas, calling them insufficient, and saying they focus too much on municipalities when corruption is an epidemic infecting all levels of government.

"It seems that these decisions came late and are not sufficient," said Javier Oliva, security expert at the National Autonomous University of Mexico. "Why now? Why after two years of government?"

"Mexico is an over-regulated country. The issue is not having more laws, but applying (current) laws," he told AFP.

- 'Cosmetic changes' -

Human rights groups voiced disappointment, with Amnesty International saying the measures are "little more than cosmetic changes that fall far short of tackling the shocking level of abuses in the country."

"The measures announced by President Pena Nieto are just like trying to fix a broken leg with a band-aid," said Erika Guevara Rosas, Amnesty's Americas director.

Pena Nieto unveiled the reforms two months after police in the southern city of Iguala, Guerrero state, attacked busloads of students, allegedly under the mayor's orders.

Members of the Guerreros Unidos drug gang told investigators they killed and burned 43 of the students after police handed them over on the night of Sept. 26-27.

The constitutional reforms will be presented to Congress on Monday, the two-year-anniversary of Pena Nieto's inauguration. Protests over the Iguala case are planned for that day.

Vowing to avoid a repeat of Iguala, Pena Nieto called for a law to disband the country's 1,800 municipal police forces and give states authority over security in every town.

But analysts said state police forces have their own corruption problems, and what they need is better training and salaries to resist the temptation of corruption.

"The problem is not how many police officers are deployed. The problem is how police are organized and governed," said Alejandro Hope, a security analyst and former Mexican intelligence officer.

- Legitimacy problem -

Pena Nieto's chief of staff, Aurelio Nuno Mayer, said the goal is to create more professional and better paid officers, like the successful example of the Nuevo Leon state police, but he admitted that purging all the bad apples would be impossible.

"Even in the best police forces in the world, there are officers who commit crimes," Nuno said.

"Will this eliminate all the ills in Mexico's police? ... The answer is no, because this doesn't happen anywhere in the world."

The top aide also said the idea of allowing the central government to take control of corrupt municipalities worked in southern Italy.

"It's a necessary condition to impose order in various parts of the country," Nuno said.

But Oliva said the Italian and Mexican cases cannot be compared, partly because in Italy, the central government gained legitimacy after the scandal-plagued main political parties disappeared.

"At the moment the authorities in Mexico have an important problem of legitimacy," he said.

Many Italian judges also paid with their lives to investigate the mafia.

"In Mexico's case, unfortunately, the judicial authorities have not joined the battle against organized crime the way they should," Oliva said.