Rebels and militia group tortured and raped civilians
Sierra Leoneans have welcomed the speed with which the United Nations war crimes tribunal has indicted a senior government politician and two former rebel leaders.
Those detained are the Sierra Leone Minister of Internal Affairs, Sam Hinga Norman, and former rebel leaders Issa Sesay and Morris Kallon of the Revolutionary United Front.
The rebel leader Foday Sankoh, who was already in prison facing treason charges, was also transferred into the hands of the court.
Sierra Leoneans had been expecting the first arrests to be made later this year.
The United Nations set up the Sierra Leone tribunal to indict and try those considered to have the greatest responsibility for war crimes committed during 10 years of brutal conflict.
The first hearings are due to start shortly.
Human Rights Watch also welcomed the indictments as key step forwards towards justice and accountability.
"We applaud the court for having the courage to indict persons who were on all sides of the conflict," said HRW official Peter Takirambudde.
A Freetown resident told the BBC: "These arrests came as a complete surprise to me. But as we all know justice has to take its course.
"Certain people have committed some terrible, unbelievable crimes against humanity, against children, against women. And somebody has to be held responsible."
People rejoiced when Foday Sankoh was first arrested two years ago
Another said: " Now that the Special Courts have taken action then this has to continue. My appeal to every Sierra Leonean is to wait for subsequent judgement and see how the trials would be conducted."
"Today the people of Sierra Leone took back control of
their lives and their future... The dark days of the rule of the gun are over," the chief UN prosecutor David Crane said.
Mr Norman, now minister of Internal Affairs, was a leader of the Kamajors militia, which supported the government during the civil war.
Both the Kamajors and the rebels were accused of widespread brutality, including rape arson and plunder of civilian property.
The RUF are especially linked to the live amputation of limbs including those of young children.
The five arrested were taken away by helicopter to a secure but undisclosed prison outside the capital.
However the court fears unrest as a result of its actions.
Our correspondent also says Mr Norman is seen by many in Sierra Leone as a hero who stood up to the rebels.
The chief prosecutor has also called on West African countries harbouring the former rebel commander, Sam Bockarie, and the former military leader, Johnny Paul Koroma, to hand them over.
Mr Koroma ruled Sierra Leone during one of the bloodiest periods of the decade-long civil war.
He seized power from President Ahmad Tejan Kabbah in 1997, but was driven out again early in 1998.
Sam Bockarie, known by his rebel name Mosquito is one of the country's most notorious rebel leaders.
He left Liberia in February last year where he had sought refuge following pressure on that country by the United Nations.
He was reported to be in Ivory Coast.
Sierra Leone's war crimes tribunal is different from those of Rwanda and Yugoslavia as it will be held in the country.
The court which is expected to last for three years is made up of both local and international prosecutors and judges.
Britain and the United States are among some 20 countries paying for the court's operations.