President Sam Nujoma of Namibia declared a state of emergency in the area, after heavy fighting broke out on Monday between security forces and separatist rebels.

Greg Barrow reports: "Questions are being asked about why security was so lax"

He told national television that 13 people had been killed in the violence in the region's main town, Katima Mulilo. At least six of these were members of the security forces.

The United States embassy has withdrawn all its peace corps volunteers and other foreign embassies were following suit, the South African Broadcasting Corporation reported from the town.

The separatists attacked an army base and police station in Katima Mulilo before seizing the offices of the state-run radio station.

A government spokesman said eight of the rebels had been taken prisoner.

The rebels of the Caprivi Liberation Front launched their armed secessionist movement last year, but the recent violence was their first known attack.

Link to Angola conflict?

Journalist Crispin Inambao: Streets deserted except for troops

The Namibian Government believes that the Caprivi separatists are being supported by the Angolan rebel movement, Unita, which fought with the South African army against the Namibian independence movement in the 1970s and 1980s.

The independent newspaper The Namibian quoted eyewitnesses as saying the rebels wore uniforms similar to those of Unita.

A Namibian soldier wounded by gunfire (Photo: Henry van Rooi, The Namibian)

The Caprivi secessionists say they are being victimised by the Namibian Government.

The government last year launched an offensive against the separatists in Caprivi after discovering one of their training camps.

In the ensuing flushing-out operation more than 2,000 people fled into Botswana.

There they were granted asylum, in a move which angered the Namibian Government.

Isolated region

A 400km (250 mile) long finger of land extending from the north-eastern corner of Namibia, the Caprivi is a territorial anomaly.

The strip of land was incorporated into the colony of German South-West Africa in the 19th century, the colonists hoping to profit from access to the Zambezi river.

In the 1970s and 1980s, under South African rule, the Caprivi became a militarised zone from which the South African army launched attacks on the Angolan-based Swapo, which was then fighting for Namibian independence.