Lawyers for survivors and relatives of dozens of people killed when apartheid police opened fire on a 1960 protest announced Thursday the launch of legal action against the South African government.

The Sharpeville Massacre was a defining point in the fight against the white-minority regime and brought the brutality and injustices of the apartheid regime to world attention.

Lawyers for Human Rights announced it would seek to overturn legislation passed a year after the massacre that prohibited legal action by the survivors and the dependents of those killed.

“The plaintiffs will argue that the Indemnity Act should be struck from the statute book,” they said in a statement.

The law had effectively extinguished all legal claims arising from the massacre and infringed the plaintiffs’ constitutional right to access courts, it said in a statement.

While apartheid-era police records indicate 69 people were killed and at least 180 wounded in the massacre, the statement said subsequent research found at least 91 people were killed and more than 238 wounded.

Many were shot in the back as they tried to flee.

Apartheid officially ended with the first all-race election in 1994.