* Angola backed Kabila and his father for two decades
* 1.4 million people made homeless in Kasai in year of violence
* UNHCR expects more refugees to cross
By Stephen Eisenhammer
DUNDO, Angola, Sept 21 (Reuters) - Captured by militia and accused of being married to a Congolese government official, Kimpanga Caro could smell the fire she was told would be used to burn her decapitated head to ash.
Caro, whose husband is a pastor not an official, was freed when one of the militiamen recognised her. She raced back home to find her husband in their ransacked village. They fled south, on foot with their five children, towards a country they heard was safe: Angola.
Thirty thousand of her compatriots have made the same journey so far, among 1.4 million people driven from their homes in a year of violence in the central Kasai region of the Democratic Republic of Congo.
There are signs that the refugee crisis is causing Angola -- a powerful regional ally that helped sustain Congolese President Joseph Kabila and his father in power for two decades -- to question its support for the leader of its volatile neighbour.
At least 3,300 people have been killed in Kasai since the Kamuina Nsapu militia launched an insurrection to force a military withdrawal from the area. Refugees say villages have been destroyed and women have been raped both by the militiamen and by soldiers who have fought them.
Their flight into the Angolan province of Lunda Norte has brought an international relief effort to the area for the first time since Angola's own 27-year civil war ended in 2002.
A cooling in Angola's support for Kabila would leave the Congolese president more isolated than ever and make it even harder for him to hang on to power beyond the end of this year, when he has pledged to hold an election already a year late.
Angola, with the third largest economy in sub-Saharan Africa and one of the region's strongest militaries, has twice in the past sent troops to prop up Kabila. Now, its soldiers are trying to contain the violence on the frontier.
Luanda has doubled its troops and police on the border, according to Marcelino Caetano, provincial director of the Service for Migration and Foreigners, responsible for Lunda Norte province's 770-kilometre border with the DRC.
"We will maintain this level of control for as long as we have to," he said in his cramped, well-guarded offices in Dundo, an old diamond mining town just 9 kilometres from the border, declining to give exact numbers for Angolan troops in the area.
Angola had pushed Kinshasa to allow U.N. officials into Kasai to help, but the Congolese have declined, he said.
Since March, two Angolan border guards and one immigration official have been killed in attacks by Congolese militia on four separate border posts, said Inacio Feliciano, a senior police commander. Aid agencies suspect Angolan forces are patrolling inside Congo, though Caetano denied this.
The unrest is not the only change that could alter Angola's policy of supporting Kabila: in Luanda, a new president is about to take power after 38 years of rule by Jose Eduardo dos Santos.
João Lourenço, a military man and former defence minister, lacks dos Santos's historic ties with Kabila and his father Laurent, who took power in Congo in 1997 and was killed in 2001.
Lourenço regards Kabila as an increasingly destabilising force, according to a diplomat familiar with his thinking, although the diplomat said military intervention against Kabila remains unlikely as it would probably make things worse.
"He doesn't want a Libya on his doorstep."
Angola has worried about the 2,600-kilometre border it shares with the DRC for decades. During Angola's civil war, enemies of the ruling MPLA party hid, trained and armed in the former Zaire. Unrest in the vast, mineral rich Congo has had a tendency to draw its neighbours into regional conflict.
With the victims of the Kasai violence now crossing into Angola and the threat of militia groups moving across the border too, the benefit of keeping Kabila as an ally is less obvious.
At the Chissanda crossing last week, located just north of Dundo, two officials said the border was closed. Guards sat around chatting and watching the sun set. Authorities say they are letting refugees cross, though the stream has stopped in recent weeks. Some are even choosing to return home.
The Congolese army says it has taken back control of Kasai, though Commander Feliciano said he had received reports of clashes around the city of Kananga on Sept 7.
Refugees interviewed by Reuters told of soldiers raping and executing residents for supporting the militia in villages the army had taken back.
"We expect it to get worse again as we approach the end of the year," said Guy-Rufin Guernas, the local head for the United Nations refugee agency (UNHCR) in Dundo.
Kabila agreed to hold presidential elections, due in 2016, by December. But the vote looks unlikely to happen by then, potentially sparking a violent backlash.
UNHCR is working on the basis that another 50,000 refugees could cross into Angola before 2017 ends. To accommodate them, a new settlement is being constructed about 100 km outside Dundo, in the municipality of Lovua. Last Wednesday, recent arrivals were digging up roots on the 25x25 metre plots of land that families are being given in this remote area of sparse forest.
Getting equipment, from solar lights to bulldozers, is difficult and expensive. Located at the north-eastern tip of Angola, Dundo's airport only just re-opened. Most goods are brought in by truck from Saurimo, the provincial capital of neighbouring Lunda Sul, three hours away. At night there is almost total darkness. Buying basic goods is difficult.
The cost of taking in the refugees is steep for Angola, which is in the midst of recession after the fall in the price of oil, its main source of wealth.
"Angola has had its own war, it understands the suffering these people are going through," said Guernas.
In Cacanda, an earlier more ad-hoc settlement where nearly 7,000 refugees are still crammed under tarpaulin before they move to Lovua, many complain of a lack of food and shelter.
Rafael Tshimbumba, 50, says the conditions may be basic but he cannot return to Kasai. He lost four children in the violence, when militias arrived at his village and began killing anyone that spoke Tshiluba, language of the Baluba people, highlighting the increasingly tribal element of the conflict.
"Here at least we are safe," he said, wearing the red and black t-shirt of the MPLA party that governs Angola.
For Caro, who escaped from Congo with her pastor husband after the militia threatened to kill her, the flight itself led only to more danger. As the family stopped to rest in a village near the border, a passing car snatched her 5-year old boy.
She searched for him for days and put a message out on the local radio, but found nothing.
"Only God knows where he's gone," she said, holding her youngest child in her arms.
(Editing by Peter Graff)
Our Standards: The Thomson Reuters Trust Principles.