An 18-year-old Libyan rebel with an assault rifle propped against his knee scans a mountain range through binoculars for signs of Moammar Gadhafi's troops.
He guards the Dhuheiba border crossing, a strategic conduit for rebels to send their families and their wounded into Tunisia and to move supplies into towns in Libya's western Nafusa mountain range.
Since rebels captured the crossing on April 21, Gadhafi loyalists have repeatedly tried to retake it, shelling it from nearby mountains, most recently over the weekend, but the rebels have held their ground.
Their red, green and black pre-Gadhafi flag flutters proudly over the border post. A motley crew of civilians-turned-fighters directs border traffic and registers the names of those crossing. On Sunday, they cleared a path for an ambulance racing to the Tunisian side with wounded from Zintan, a mountain town where 10 rebels were killed and 30 wounded in a weekend battle with regime forces.
Control of the crossing has turned Tunisia into a rear base and is helping the rebels hold out against Gadhafi's troops in the mountains _ along with the coastal city of Misrata the only area of resistance in western Libya.
Thousands of women and children from Nafusa towns have found refuge in tent camps and with families in Tunisia. Wounded fighters are treated free of charge in Tunisian hospitals. Trucks deliver supplies from Tunisia to Nafusa.
Tunisia has tried to avoid taking sides, careful not to get drawn into the conflict just four months after its own successful uprising set off a wave of anti-government revolt across the Arab world. Libya's rebellion against Gadhafi erupted just a month after Tunisians threw out their longtime dictator, Zine El Abidine Ben Ali.
"We're not going to get involved in a war with a country facing big problems," Tunisian Prime Minister Beji Caid Essebsi said Sunday on Tunisian TV.
Staying on the sidelines isn't always possible, however. Dozens of shells have overshot their targets, including 80 alone on Saturday, landing in Tunisia near the border town of Dhuheiba. After one failed attempt to retake the crossing last month, Libyan forces in armored vehicles fled into Tunisia, were disarmed by Tunisian troops and sent back to Libya.
Tunisia's Foreign Ministry summoned the Libyan ambassador two weeks ago and demanded that the Gadhafi regime respect Tunisian sovereignty. Over the weekend, it deplored a "lack of seriousness in the commitment made by Libyan authorities."
For Libyan civilians and rebels, Tunisia offers a brief respite from the trauma of war.
Dhuheiba's small clinic, now run by the Tunisian military, is the first stop for the wounded before they are taken to Tunisian hospitals farther away.
On Sunday, a 28-year-old from Zintan was brought in with blood seeping through a dirty bandage on his right hand. He'd been shot toward the end of a daylong battle Saturday, which he said ended with Gadhafi's forces being pushed back.
The fighter, wearing a camouflage jacket over his traditional white robe, said the rebels were better motivated that their foes because they were defending their homes.
"I am also fighting for a better life," he said, noting that he is unemployed despite a university degree in business administration.
Like other Libyans interviewed on the border, he spoke on condition of anonymity for fear of reprisal by the Gadhafi regime.
Most of the men of Zintan have joined the fight, he said, including his 57-year-old father. The older man also was wounded Saturday, shot through the pelvis, and arrived in Dhuheiba in the same ambulance as his son.
Zintan's clinic is overwhelmed and underequipped, the younger man said, suggesting that some fighters who died Saturday could have been saved with proper treatment.
Random shelling of civilian areas and persistent rumors that Gadhafi's troops are raping women have prompted thousands to flee the Nafusa area. More than 50,000 Libyans have streamed into southern Tunisia through the Dhuheiba crossing since fighting began in mid-February, said Andrew Harper of the U.N.'s refugee agency.
The New York-based Human Rights Watch has said the indiscriminate shelling of civilian areas, as a pattern, violates the laws of war. It said Libyan refugees from the Nafusa area gave "consistent and credible accounts" of such attacks.
Libyan government spokesman Moussa Ibrahim dismissed the report. "Human Rights Watch needs to grow up," he said, and "stop accusing us of crimes while they sit somewhere in Europe ... listening to dubious phone calls by some fake eyewitnesses." He said the group should establish an office in Tripoli.
Several tent camps for refugees have been set up in Tunisian towns, including Remada, about 25 miles (40 kilometers) from the border.
In the Remada camp, about 20 women sitting on the floor of a larger communal tent watched TV, waiting for Libya updates on Al Jazeera.
A 14-year-old girl, sitting cross-legged, had draped a homemade rebel flag over her shoulders, saying it comforted her. The girl, who gave her first name as Sarah, said her father and most male relatives stayed behind in Nalut to fight, adding that she hasn't heard from them since she and others fled two weeks ago. In Nalut, stories of rape she'd heard from western Libyan towns that fell to Gadhafi's forces kept her awake at night, she said.
In another tent, stifling from the desert sun and swarming with flies, a 17-year-old girl said she last spoke to her 24-year-old fiance, one of the Zintan fighters, a week ago. Three of her brothers have also joined the battle, she said. A day earlier, she learned that a cousin had been killed.
More than 3,000 refugees are in tent camps, but most are in Tunisian homes. Family ties reach across the border _ many on either side belong to the ethnic Berber minority _ but other Tunisians have invited strangers into their homes. The generosity is particularly remarkable because the region is one of the poorest in Tunisia, with double-digit unemployment.
In the town of Tataouine, one volunteer group said it has found hosts for 805 refugee families and gives them basic goods like noodles, milk, diapers and mattresses, all donated. The U.N. has also started handing out supplies, and aid officials said the international community must do more for the refugees.
Back at the border post, computer teacher Morad Hamed and engineer Morad Mehdi sat on old chairs, also keeping watch, their rifles by their side. Wearing a shirt with the insignia of the Chelsea football club, Hamed, 28, said he misses his old life and his pregnant wife, whom he hasn't seen for two months.
But he added that there's no going back.
"We are fighting for our freedom," he said.
Associated Press writer Bouazza Ben Bouazza in Tunis, Tunisia, contributed to this story.