"These sentences will hopefully serve as a deterrent to those whose acts undermine or threaten state security," it said in a statement.

The government and the DA welcomed the sentences handed down on Tuesday to the Boeremag members convicted of high treason.

"The decade-long trial shows how the attainment of freedom and democracy has changed the lives of the people in the country," government spokesman Harold Maloka said in a statement.

"Government commends the investigating and the prosecution team for the sterling work, and hopes that these sentences will act as a deterrent to those who threaten the stability of our hard fought democracy."

The High Court in Pretoria imposed sentences ranging from five to 48 years' imprisonment on the group's members.

The justice department also welcomed the sentences.

"These sentences will hopefully serve as a deterrent to those whose acts undermine or threaten state security," it said in a statement.

Democratic Alliance justice spokeswoman Dene Smuts appealed to the media to allow the orphans of Soweto mother Claurina Mokone to absorb the news of the sentencing in private.

Mokone was killed when a piece of steel dislodged by a bomb the Boeremag planted on a railway line landed in her shack.

Smuts, who helped set up a trust for the children, said that Mary and Joseph Mokone had moved on with their lives.

"They have received education, as was Claurina's dearest wish.

"In Joseph's case, this continues at university, and Mary achieved a business qualification and works in the private sector," she said,

Smuts said it was hoped there would be no further appeals after the trial, which was the most expensive in South African legal history.

Earlier, Boeremag leader Tom Vorster and some members of its "bomb squad" which blew up numerous targets in 2002 were sentenced to in effect 25 years' imprisonment.

Bombers Herman van Rooyen, Johan and Wilhelm Pretorius, and Rudi Gouws received the same sentences as Vorster.

The third Pretorius brother, master bomb maker Kobus Pretorius, was sentenced to 20 years' imprisonment, of which 10 years were suspended.

This was because Pretorius had a change of heart during the trial and expressed remorse for what he did.

The members of the bomb squad were sentenced to an additional 13 years' imprisonment on charges of culpable homicide and conspiring to murder former president Nelson Mandela.

Judge Eben Jordaan said Mandela would have been killed by a landmine planted by the Boeremag bomb squad had not arrived by helicopter to open a school in Bolobedu, Limpopo.

This would have caused chaos and bloodshed in the country.

Jordaan said the Boeremag's aim had been to destroy democracy in South Africa.

The bombers had five large car bombs ready for targets in the city centres of Pretoria and Johannesburg and were planning further bomb attacks when they were caught.

Boeremag leaders Mike du Toit, Dirk Hanekom and the Pretorius brothers' father, Dr Lets Pretorius, were each sentenced to 30 years' imprisonment, of which 10 years were conditionally suspended for five years.

Mike du Toit's right-hand man, Andre du Toit, and Dion van den Heever, were each sentenced to 20 years' imprisonment of which 10 were suspended.

Rooikoos du Plessis and Jurie Vermeulen, who also played important roles in planning the coup, each got 15 years', of which 10 were suspended.

One of the Boeremag's most active members and the Boeremag chaplain, 74-year-old Vis Visagie, was sentenced to five years of correctional supervision.

Five of the Boeremag members who played a lesser role, including the youngest member Jacques Jordaan, walked out of the court free men after being given suspended sentences. They are Adriaan van Wyk and former defence force officers Giel Burger, Jacques Olivier, and Pieter van Deventer.