GWEN IFILL: We turn now to the first of several stories this week from the Western African nation of Mali.
Islamic militants have reportedly seized control of two-thirds of the country. They have imposed strict Sharia law, terrorized residents, and prompted hundreds of thousands to flee.
Lindsey Hilsum of Independent Television News reports.
LINDSEY HILSUM: Al-Qaida has a new refuge, the deserts of northern Mali. They drove out the national army and seized their weapons. Now they fly the al-Qaida flag. They control an area twice the size of Britain, including cities and airports. And they're threatening Europe.
OMAR OULD HAMAHA, Defenders of the Faith (through translator): When we have conquered France, we will come to the USA. We will come to London and conquer the whole world. The banner of Mohammed, peace be upon his head, will be raised from where the sun rises to where it sets.
LINDSEY HILSUM: The military commander of al-Qaida's local ally, Ansar Dine, Defenders of the Faith.
Four hundred miles south, in the Malian capital, Bamako, a makeshift populous militia trains every evening on a football pitch, their mission, to take the north of their country back from the Islamists.
Self-defense units like this are springing up across the country now. The people have got no faith in the army to defend them because they saw how the soldiers fled the moment the rebellion started in the north.
But militias, some of them braced on tribe, can be very dangerous. And there's no rule of law in Mali now.
On the night of April the 1st, Islamists and local rebels Tuareg drove into Timbuktu. They had seized 87 pickups from the army, gift of an American anti-terrorism program. By dawn, they were in control.
The Malian jihadists are backed by al-Qaida in the Islamic Maghreb, renowned kidnappers of Westerners.
The local people are suffering. Mobile phone footage shows a teenager being whipped for smoking. Mali's capital is desperately poor. But nearly 200,000 northerners have fled here nonetheless. They're staying with friends and families.
Traders and shop keepers are finding it hard to survive in Islamist-controlled towns like Timbuktu.
MOHAMED DICKO, shopkeeper (through translator): When they come into our shops, they don't ask permission to search our bags. When they find cigarettes, they just take them.
So now I have to hide the cigarettes. My customers ask, have you got any secrets? That's what they call them now. We have changed the name.
LINDSEY HILSUM: Near the town of Segou, a few hours' drive from the capital, we went to see how what remains of Mali's army is trying to regroup.
Today, we have naming of parts. They're learning to dismantle a heavy machine guns. It's pretty basic stuff.
After the soldiers fled the north, a junior officers coup deposed Mali's weak and corrupt civilian government. Outside powers are reluctant to lend their support until the soldiers give way to a genuine new civilian administration.
Aiming practice, but no firing -- they're short of ammunition and blanks -- of everything really.
LT. CHEICKNE KONATE, company commander: We need every support, air support, ground support, logistics support, personnel support, experienced support. Anything, we need it, because we are in need today.
LINDSEY HILSUM: In Bamako, life looks normal here. But paralysis pervades the shiny government buildings.
West African states have offered to stabilize a new civilian administration, but the soldiers refuse to move aside.
As long as the authorities resist international intervention, Mali is drifting. Aid has been cut. People are getting poorer. There's no solution in sight.
TIEBILE DRAME, former foreign minister, Mali: The situation is serious. The rest of the world shouldn't stay just to look at the situation. We should be helped, unless they would like to see another Somalia or another Afghanistan.
LINDSEY HILSUM: Friday prayers in Bamako -- 98 percent of Malians are Muslims, but that doesn't mean they can tolerate life under harsh Islamic rule.
Senior clerics are trying to negotiate with the jihadists, but all the while, al-Qaida is strengthening its hold on the north. And no one as yet is doing anything to stop them.
GWEN IFILL: Late today, state television in Mali reported that the country has formed a new government.
In her next stories, Lindsey Hilsum looks at refugees who have fled to Mauritania and the destruction of Mali's cultural heritage.