Mexico City, October 23 (RHC-Xinhua) -- Renowned intellectuals from around the world have joined an international outcry demanding justice in the case of 43 students missing since late September in Mexico.

In an "Open Letter From Abroad" -- addressed to Mexico's President Enrique Peña Nieto and his cabinet -- professors and writers, including Noam Chomsky from the United States, called for the "return of the 43 students, alive," and the immediate ouster of officials with links to or knowledge of the crime.

The letter, published online in five different languages, was delivered Tuesday and Wednesday to Mexican embassies and consulates around the world, with more than 7,500 signatures representing the international academic community "of more than 60 countries and 500 universities."

The students were abducted on September 26th reportedly following a clash with municipal police in the city of Iguala, the country's southern state of Guerrero, which also left six dead. Pressure has been mounting on the government, which was initially slow to react, to locate the missing students and apprehend those responsible.

A search operation has so far uncovered nearly 20 mass graves in and around Iguala, but none of the bodies have as yet been identified. The incident has blown the lid off the extent of collusion between authorities in Guerrero and local drug trafficking rings.

"What is the size and number of mass graves in this country, how many more bodies fit in them...?" the signatories asked, calling for a serious investigation of the crimes. "Neither the names of those captured nor the direction of the investigation have been revealed," wrote the academics.

In Mexico, "it is no longer possible to speak of common criminals but rather of the criminality of government representatives at the local, state, and federal levels," the letter stated.