In remote north Darfur, an upsurge in clashes between rebels and government forces

JEM rebels, who have seized two key towns, have stepped up the fight to create a 'liberated' zone. Peace talks are scheduled for Wednesday.

The eyes of the government soldiers being driven away by their rebel captors showed no sign of fear. Instead, their expression betrayed a mix of exhaustion and relief.

Sitting on top of empty ammunition cases aboard a government truck seized by rebels, many of the young soldiers had the dark skin, long limbs, and ritual scarring of Southern Sudanese tribes.

The presence of the Southern Sudanese soldiers in this remote part of north Darfur is a vivid reminder that Khartoum has few allies here.

Darfuris do serve in the Army. But Khartoum does not trust them, and instead sends in soldiers who have little interest in the six-year war here, and less interest in losing their lives to a better motivated local guerrilla force.

So when guerrillas from the Justice and Equality Movement (JEM) lined up their technicals – pickup trucks mounted with Katyusha rockets and heavy machine guns – around the town of Kornoi, many of Khartoum's soldiers simply turned and ran.

Their mud-brick barracks were left in disarray: camouflage jackets still hung from doornails, dinner bowls littered the floor, and a concrete arms bunker was left filled with bombs for helicopter gunships.

The fighting was over within two hours.

Rebels push hard ahead of rains

The past fortnight has seen an upsurge in clashes as rebels try to claim a "liberated" zone ahead of rains due to begin within a couple of weeks.

In return, government Antonov planes have pounded targets every morning and evening, while rebels seek out whatever cover they can find in Darfur's empty desert.

Peace talks between the two sides are set to resume in Qatar on Wednesday. But with fighting on the increase and trust at rock bottom, few experts hold out hope for any major breakthroughs.

Lt. Gen. Suleiman Sandal, the deputy commander of JEM, says the government had already gone back on earlier promises.

"We signed the good intentions agreement to see if the government had good intentions or not. We asked them to release our captured brothers in Khartoum and not execute them," he says, sitting cross-legged on a woven carpet spread in the shade of a spindly thorn tree. "The government has refused to release these prisoners."

The interim agreement drawn up in February also required the government to ease conditions for aid agencies operating in Darfur.

However, in March, Khartoum expelled 13 international nongovernmental organizations helping to deliver vital aid to more than 4 million people.

The move came in response to the International Criminal Court's decision to issue a warrant for the arrest of President Omar al-Bashir, who is accused of seven counts of war crimes and crimes against humanity for his role in a conflict that has killed at least 200,000 people.

In the past year, the war has settled into a low-intensity phase, in sharp contrast to the early days, when government-backed janjaweed militias launched a scorched-earth campaign to deprive rebels of civilian support.

These days, death comes in ones and twos, with bombs dropped from Antonov warplanes. Or it comes day after day in the aid camps, as fragile children succumb to diseases of malnutrition and want.

Sudan and Chad step up proxy war

At the same time, Sudan and Chad have stepped up their proxy war. Chadian war planes have been operating deep into Darfur seeking out bases of Khartoum-backed rebels who launched attacks inside Chad earlier this month.

JEM's offensive brings the risk of Sudanese reprisal against its own bases across the border, turning a war by proxy into a real front line.

General Sandal says that JEM was now trying to set up a "liberated zone" allowing aid workers to deliver help from Chad.

"In the past, our strategy has been to have mobile units. To hold areas with civil administration takes a lot of effort," he says. "After the government expelled the 13 NGOs, we thought deeply and realized the IDPs [internally displaced persons] are in a very difficult position."

Jem is currently positioning itself as the only rebel group worth talking to in Darfur. In recent weeks, its ranks have been bolstered by commanders from the region's numerous rebel factions.

However, its leadership is still drawn predominantly from the Kobe clan of the Zaghawa tribe, and its fighters include children often recruited from the Chadian refugee camps.

For the time being, it has secured two important victories, seizing Kornoi and then Um Barru, days later.

Dust clouds and intense heat

A column of fighters – with at least 100 "battle wagons" – has been camped around Kornoi for the past week, dodging Antonov raids.

Each vehicle contains a mobile fighting force, usually equipped with one heavy and one light machine gun, along with a couple of rocket-propelled grenade launchers.

The pickups are smeared with mud to make them invisible from the air.

A dry wind whips sand into dust clouds at this time of year, providing extra cover but making life all the more difficult in temperatures that top 100 degrees F.

The soldiers spend their days sprawled on blankets under trees waiting for their next orders.

Every morning and every evening, the Antonovs have been in the air, making tighter and tighter circles as they try to zero in on rebel positions around the captured town. The sound of bombing shudders across the desert.

Kornoi itself was abandoned at the start of the conflict, at a time when the janjaweed were burning and looting their way through the first years of the war.

Its population, from the Zaghawa tribe, was from the same group as many JEM recruits.

Today they live mostly over the border as refugees in Chad.

A few have begun dribbling back to Kornoi, to water their donkeys or reclaim looted shops.

Bagheat Yacoub Tahib was selling cold sodas stacked up in a porous clay pot filled with water – the closest thing here to a fridge.

He says he wants to bring his family back from Chad once the Antonovs stopped flying overhead.

"We were afraid of coming to the town because the government was here," he says. "Now things are safer."