Jakarta – Thousands of soldiers and police remained on alert in the capital and other cities Tuesday as Indonesia prepared to mark the anniversary of what the government says was a failed communist coup 33 years ago. The military has warned that anti-government groups might use Wednesday's anniversary as an excuse to stage protests.

Rumors of possible unrest have spread through the city of 11 million people during the past week, despite the presence of troops and police across Jakarta. The heavy security has been in place for almost a month to counter rising student protests against the government, which is struggling under the weight of the worst economic crisis since the coup attempt more than three decades ago.

Jakarta police spokesman Lt. Col. Edward Aritonang downplayed the significance of the rumors, but said security personnel would remain on alert. "Jakarta is safe as usual," he said.

Sept. 30, 1965, was a bloody turning point in the history of the sprawling Southeast Asian nation. Six army generals were executed and their bodies tossed down a well on the outskirts of Jakarta. The military at the time blamed communists for the murders and swiftly crushed what they said was a coup attempt.

The operation was led by Suharto, then a major general, who later replaced Indonesia's founding President Sukarno as head of state. Tens of thousands are said to have been slaughtered in a backlash against leftists during the following months. The burgeoning Indonesian Communist Party was decimated and remains banned to this day.

The government solemnly commemorates the anniversary of the 1965 events every Oct. 1, the date the alleged plotters were stopped. Last week, Indonesia's military claimed that university students were planning to hold demonstrations across the country Wednesday. However, student leaders have denied this.