Former Argentine army general Luciano Benjamín Menéndez, convicted of crimes against humanity, has died aged 90.

He was sentenced to life imprisonment for kidnapping, murdering and torturing hundreds of opponents of Argentina's brutal military regime.

Menéndez, also known as "The Hyena," was the military commander of ten Argentine provinces from 1975 to 1979.

Some 30,000 people are estimated to have been killed by the military in its infamous Dirty War against dissidents.

Menéndez was also convicted for abducting children from detained anti-government activists and giving them up for adoption.

The children were often adopted by families of military officials, who strived to give them a non-communist upbringing.

For his crimes, Menéndez was sentenced 12 times to life in prison.

He died in hospital in the central city of Córdoba, where he was based in the 1970s.

Menéndez was under house arrest, having served time in jail.

He began carrying out operations against left-wing activists during the government of President Isabel Martínez de Perón in the mid-1970s.

When the junta led by General Jorge Rafael Videla seized power in March 1976, he expanded his activities.

Human rights groups estimate that more than 2,500 people were taken to La Perla clandestine detention centre in Córdoba province.

Survivors say almost all women detained there, and some of the men, were sexually abused.

Hijos, a campaign group founded by the abducted children of anti-government activists, posted a note on Twitter calling him a "mass murderer" and saying he was responsible for genocide.

The Grandmothers of the Plaza de Mayo, Argentina's best-known human rights group, has so far managed to identify through DNA testing 126 children stolen from their parents during military rule, between 1976 and 1982.

Argentina's military regime

1976: General Jorge Rafael Videla seizes power - thousands of political opponents rounded up and killed

1982: Videla's successor, General Leopoldo Galtieri, orders invasion of British-held Falkland Islands

1983: Civilian rule returns to Argentina, investigations into rights abuses begin

2010: Videla sentenced to life imprisonment for murders during his term in office

2012: Videla sentenced to 50 years for overseeing systematic theft of the babies of political prisoners

2013: Videla dies in prison, aged 87