In this Tuesday, June 2, 2009, file photo, former South African President Nelson Mandela reacts at the Mandela foundation, in Johannesburg, South Africa, during a meeting with a group of American and South African students. (AP Photo/Theana Calitz-Bilt, Pool, File)

WASHINGTON (AP) — The FBI investigated multiple death threats against former South Africa president Nelson Mandela during his 1990 visit to the United States and also used an informant to learn details about his trip, according to newly released documents.

The FBI released hundreds of pages of records tied to Mandela’s visit, which came months after the anti-apartheid leader was released from a 27-year prison sentence.

Many of the documents are redacted, but they do show the FBI investigated multiple threats to assassinate Mandela during his trip, including a handwritten note that says, “Remember John F. Kennedy in Dallas???” One threat was phoned into a university in Georgia where Mandela was scheduled to address a rally.

Mandela, who became South Africa’s first black president after the end of apartheid in 1994, died in December at the age of 95. Jailed under racist rule, he played a critical role after his release from prison in moving the country out of the apartheid era to an all-race democracy.

The documents were posted on the FBI website in response to Freedom of Information Act requests.