Assata Shakur, an activist with the Black Liberation Army exiled in Cuba for four decades, has died in Havana, aged 78.

Shakur, also known as Joanne Chesimard, died Thursday of unspecified health conditions and advanced age, Cuba's foreign affairs ministry said in a statement on Friday.

She had been on the FBI's Most Wanted Terrorists list for years after she escaped in 1979 from a New Jersey women's prison, where she was serving a life sentence following her murder conviction in a shootout that killed a New Jersey state trooper and a fellow activist.

Shakur maintained her innocence and reappeared in Cuba in 1984, where she was granted asylum by former president Fidel Castro.

Born JoAnne Deborah Byron in July 1947 in New York City, she was raised between the city and Wilmington, North Carolina. She was the step-aunt and godmother of the late rapper Tupac Shakur.

Shakur became involved in political activism for black Americans while in college, first with the Black Panther Party, which favored radical resistance to racism and developed social services for black people.

The movement was heavily surveilled by the FBI, which considered it a threat to the US. Shakur later joined the more radical Black Liberation Army, composed of former Black Panthers.

In 1973, while traveling with fellow activists, their car was stopped by New Jersey officers, leading to a shootout that killed state trooper Werner Foerster and fellow activist Zayd Malik Shakur. Assata Shakur was also injured during the incident.

She was arrested and tried for Foerster's death, asserting her innocence and claiming that her trial was unfair due to an all-white jury.

In a 1998 interview filmed in Havana, she expressed that she escaped because she feared for her life and believed she would never receive justice in the US.

Her time in exile has remained a contentious issue in US-Cuba relations.

Shakur was the first woman added to the FBI's Most Wanted Terrorists list, with both the FBI and New Jersey offering a $1 million reward for information leading to her capture.

In music, Shakur is celebrated, being referenced in songs such as Rebel Without a Pause by Public Enemy and A Song for Assata by rapper Common.

She is survived by her daughter, Kakuya Shakur, who expressed her profound loss on Facebook, stating: Words cannot describe the depth of loss that I am feeling at this time.