Human rights activists who gathered in Brazzaville have called on African states to do more to prevent the enforced disappearance of citizens and to end the impunity that often accompanies such crimes.

Representatives from the International Human Rights Federation (FIDH) and other NGOs were meeting in the Republic of Congo capital ahead of the 42nd session of the African Commission on Human and Peoples' Rights, which runs until 28 November.

"Rarely are people who commit such crimes brought to justice," said Sidiki Kaba, FIDH's former president. "Impunity or denial of justice creates a social climate in which no confidence in the institutions can exist. If enforced disappearances remain unpunished, the memory of the disappeared will haunt the societies in which such acts are committed for a long time."

For Joachim Bandza, a columnist with the Roman Catholic Semaine Africaine (African Week) newspaper, the official silence surrounding enforced disappearances tends to exacerbate rather than quell insecurity.

"A country that respects its dead must honour their memory. Conversely, scorning victims will only lead their families to seek justice elsewhere; a totally understandable reaction because injustice always fosters a spirit of vengeance," he said.

The human rights groups also asked all African Union member states to ratify the International Convention for the Protection of All Persons from Enforced Disappearance, which was adopted by the UN General Assembly in December 2006. While several African countries have signed the convention, none have ratified it. Twenty states must ratify the convention for it to come into force.

The convention defines enforced disappearance as any form of detention by state agents where the very act of detention, or the fate or whereabouts of the detainee is kept secret, thereby placing the detainee outside the protection of the law.

FIDH president Souhayr Belhassen said: “[The NGOs had] urged African states not to lodge official reservations when signing up to the convention, to recognise the competence of the Enforced Disappearance Committee [established under the convention] to rule on individual cases, to ensure effective national legislation incorporating the convention is passed and to publicly support and promote the convention.”

Kaba characterised the practice as a human rights violation as serious as torture or murder, saying it forced relatives to endure the pain of uncertainty over whether the missing person was alive or dead.

The human rights groups said that in the 1960s, and even more frequently in the 1970s and 1980s, many African leaders resorted to enforced disappearances to silence their opponents and human rights campaigners. Members of opposition groups were systematically picked up and held illegally in secret detention centres.

According to Nassera Dutour, spokeswoman for an Algerian group of missing people known as Le Collectif des Familles des disparu(e)s en Algérie, thousands of people, mostly men, in her country were either picked up by security forces or militias and disappeared in the 1990s.

"Today, a lot of African countries, especially those with ongoing armed conflict, are affected," said Floribert Chebeya Bahizire, president of the Voice of the Voiceless in the Democratic Republic of Congo.

"Although information on missing people is often very difficult to come by, human rights NGOs have established that this violation still occurs in Africa," he said.

Amnesty International has released a report highlighting the cases of several army officers who disappeared in Chad in 2006 after having been suspected of aiding and abetting rebel fighters who planned to attack the capital, N'Djamena.

In a September 2007 report, Human Rights Watch said enforced disappearances were common in the Central African Republic.

According to the UN, 535 new cases of enforced disappearances were reported in 2005 and some 40,000 people in 90 countries have disappeared since 1980.