JUDY WOODRUFF: Next: to the West African nation of Mali.
Earlier this week, Lindsey Hilsum of Independent Television News reported on Islamic militants who now control two-thirds of the country. Violence and harsh punishments carried out by the militants have driven thousands to flee to neighboring Mauritania.
Tonight, Hilsum has the stories of families crossing the border.
LINDSEY HILSUM: It's been a long journey, three days' trek through desert. Another seven families who have loaded everything they have onto their carts and crossed the border into Mauritania. Fear and hunger drove them out of Northern Mali.
They tell their story to the police chief in the border town of Fassala.
DEYDA MOHAMED, police chief (through translator): They say that the fear of having a hand amputated or being whipped or stoned to death made them come. They will not accept these things. They're Muslims, but they can't endure this kind of religion being imposed upon them.
LINDSEY HILSUM: About 400 Malians arrive every day with similar tales of fighting between armed groups and terror being administered by al-Qaida and its allies in and around Timbuktu.
The people coming across the border paint the picture of a region that's descending into chaos. There's less and less to eat, they say, and they cant afford the prices in the market.
But worse than that, they're terrified of the armed men who are roaming Northern Mali and imposing their version of Sharia.
The Tuaregs of Northern Mali are used to a tough life, but not like this.
MAULUD IBRAHIM, Malian refugee (through translator): We're frightened because there's no government we can trust to protect us from the armed groups.
LINDSEY HILSUM: They have heard on the radio that foreign powers may attack the Islamists with drones or fighter bombers.
MAN (through translator): What I'm afraid of is being bombed from the air.
LINDSEY HILSUM: A few months back, the Tuaregs were celebrating. They seized weapons from the Malian army, to add to those they'd been given by Colonel Gadhafi of Libya, and claimed Northern Mali as an independent Tuareg state, flying their own flag.
But al-Qaida hijacked their victory. The Tuaregs and local Islamists fought in Gao and other towns.
The Tuareg separatists were pushed out and the Islamists prevailed. Now the al-Qaida flag flies over Northern Mali. So many Tuaregs are being forced into exile.
The journey from the border to the refugee camp isn't easy, especially in the rainy season, pastures new, but not for the refugees, who face a life of uncertainty. Mbera camp is 1,000 kilometers from the Mauritanian capital in a remote and inaccessible corner of the Sahara -- 100,000 people are living here, and more come every day.
At least in the camp they have water and the basics they need to survive. Fatima Sidi Mohammed's makeshift dwelling collapsed in the rain and wind. Her neighbor is helping her build another. She tells me that she spent all her money hiring a vehicle to get to Mauritania, and now she has nothing.
In the clinic, they're treating diseases caused by malnutrition and poor sanitation. Health centers in the villages around Timbuktu have stopped working, and the Islamists prevent women from leaving their homes.
SALLAMA MINT DELLS, Malian refugee (through translator): We're scared of everyone. You can't even go out to buy food because your life is at risk. In the camp, at least we feel safe and we're given food.
LINDSEY HILSUM: Sallama Mint Dell's grandson Hasan is getting treatment now. If he's in danger, it may be too late.
The young men tell me they have neither jobs nor education. Northern Mali's always been deprived. The Tuareg blame both the Malian government and the Islamists for their misfortune.
MOHAMED ALY AG ALMOUBARACK, Mauritania (through translator): The Tuareg are victims, just as the north is a victim. We expected that, because you can't have what you want without suffering. You can't get your identity without pain, without dying, without taking all the risks in the world.
LINDSEY HILSUM: Refugees gather to listen to the griot. It's a traditional form of storytelling through music. The Islamists have banned musical instruments and singing.
Here in Mauritania, at least the Tuareg are free to tell their story, how they fought for independence, but got exile instead.
JUDY WOODRUFF: In her final report, Lindsey Hilsum visits Timbuktu to assess the destruction of mausoleums and shrines in the ancient city.