The graves of victims of some of Algeria's recent massacres

They said the man, identified as Mohamed Kebaili, known as Ayachi, was killed with three other suspected militants after the security forces laid siege to an apartment near the airport.

They said he was head of GIA in Algiers.

The authorities said that two children and a member of the security services were also killed. The security services reportedly rushed the apartment in which the GIA leader and other members of the group were hiding.

Shoot-out

Reading about the latest massacre has almost become routine

Journalists who had been at the scene said that police, elite troops and soldiers were involved in the operation which started on Monday and seems to have lasted for almost 20 hours.

They said that before the final assault, a man firing a Kalashnikov tried to shoot his way out of the building before he was gunned down.

The announcement that Mohamed Kebaili was among those killed came several hours after the end of the operation.

'Orchestrated massacres'

North Africa Correspondent Heba Saleh reports

The authorities said he was behind many killings of civilians including two large-scale village massacres last summer in which several hundred people had their throats cut.

These massacres, just south of the capital, had focused world attention on the conflict in Algeria and also led to calls for an international inquiry into the violence. Despite taking place very close to army barracks, no one came to the rescue of the villagers, and there were no immediate attempts to pursue the aggressors.

The BBC North Africa Correspondent says the announcement that the man behind the massacres has been killed does not necessarily mean organisations such as the human rights group Amnesty International would drop their demand for an inquiry.

Most militant

The GIA is blamed for much of the violence against civilians in Algeria.

It is the most militant of the Islamic groups that turned to violence after the authorities cancelled elections in 1992, which Islamic parties seemed sure to win.