Saudi-backed forces gather on Yemen border as separatists face pressure to pull back

Forces of the Southern Transitional Council arrive in a mountainous area where they are launching a military operation in the southern province of Abyan, Yemen, on Monday. Photograph: Reuters

As many as 20,000 Saudi-backed forces are gathering on the border of Yemen as the separatist Southern Transitional Council comes under pressure to withdraw from the huge territorial gains it has made in the last month in the vast, oil-rich governorate on Hadramaut in eastern Yemen.

The STC is using its advance to raise its demand for Yemen to revert to two states, north and south, as it had been until 1990.