The Namibian army has begun pursuit operations against Angolan Unita rebels, following an attack in which three French tourist children were shot dead.

Namibian radio said soldiers had crossed the border into Angola in search of 10 gunmen.

It added that Namibian troops had been involved in a clash near Kongola in Namibia's Caprivi province, which is the first time the Namibian army and Unita are known to have clashed on Namibian territory.

The radio did not say whether the clash - in which seven Unita fighters were killed - was connected with the hunt for the tourist attackers.

Four suspected Unita fighters are reported to have been arrested near Mashare, futher east in the Caprivi.

Cross-border conflict

Army chief-of-staff Major General Martin Shalli said the army would be carrying out operations against "groups responsible for the atrocities".

"Any terrorist action by Unita on Namibian soil will be revenged, even if it means taking limited operations into Angola," he said.

Namibia has previously avoided getting involved in the Angolan civil war, but in December it allowed the Angolan Government to use bases within Namibia to launch attacks on Unita.

Unita troops have begun to cross into Namibia since then.

Namibia blames Unita for two gun attacks on Monday, one of which killed the three children and injured their parents, and the other which injured two aid workers.

Unita has denied the charge, blaming the killings on Angolan Government troops.