THERE is a reason why Libya's rebel forces have failed to declare victory across the country, and it is to be found in Bani Walid.
For the third time in 10 days, Gaddafi troops in the town fought a tough, well-organised rearguard action, driving back a concerted rebel assault, and sending first casualties and then the rebel brigades back towards Tripoli.
The rebels claimed they had captured the bodyguard of Saif al-Islam, Col Gaddafi's son, as they fought street-to-street battles in the city.
They said the bodyguard, who was taken to a makeshift prison at a rear checkpoint north of the town, was the best evidence yet that Saif al-Islam, long touted as his father's heir, has been marshalling the town's defences.
He had yet to be interrogated but, according to Sadiq Daaeki, a supervisor at the prison, Saif al-Islam had been in the town until yesterday morning, staying at the house of a civil leader.
One story among rebels surging on Bani Walid during the afternoon was that Saif al-Islam had left early in a convoy of 30 SUVs across the desert, after a diversionary attack on a checkpoint.
"This is why they are defending so strongly," said Ismael Abouda as he withdrew. "I think Gaddafi himself is there, because this is the hardest fight we have been through."
Like all such claims, they have been heard before and there is little proof. The Gaddafi forces seem to be able to defend themselves, whoever is in charge.
Yesterday's was the second major assault to reach inside the town itself, launched with the customary confidence of the rebel brigades.
Even as Jeeps and pick-ups poured north out of town carrying the wounded, rebels insisted there would be no retreat. "We are still pushing on. It is difficult but there will be no retreat," said Abu Bakr al-Atrash.
But Bani Walid has proved the toughest obstacle in the long war for the anti-Gaddafi forces. The residents are divided and now many sympathetic to the rebels have left and those that remain are hostile.
As happened last Sunday, rebels swept past the university and established themselves in Wadi Zeitoun, a valley in the northern half of the town. But two hills dominate the centre, and the defenders used them to fire down on their attackers. They poured diesel down the roads, preventing the armed pick-up trucks getting a grip. But as the fighters went ahead on foot, they were ambushed.
"We were shot at from behind," said Nabil Darawi. "We don't know where from."
As the rebels tried to re-group, their positions were targeted within minutes, leading many to repeat allegations that traitors were among them. More likely they could not escape the binoculars on all sides of the Gaddafi forces and their local supporters.
"We saw civilians but they were with Gaddafi," said Mr Abouda, who, during term-time, is studying hospitality management.
The mortars caused serious injuries. After one barrage sent dust into the air, cars swept into an advance point on the outskirts of town, where ambulances were waiting to take the injured down the road.
They were carried out, two with shattered legs and one unconscious, and, as the rebels began to panic, were taken to Tarhouna, the next city to Bani Walid. They were followed by streams of pick-ups in full retreat, mortar blasts trailing behind them down the road.
Some rebels were holding on, but their position seemed hopeless. "We need more than this. We need tanks and Grad rockets," said Mohammed al-Wan. "We don't want to leave, but we have nothing to hit back with at the snipers."
Outside the mosque at the hamlet of Wishtata, 20 miles from town, arguments broke out and, crying out for a lack of leaders, fighters said they were not just retreating but heading home, to Zawiya, to Tripoli, to Tobruk.
The retreat was as demoralised as the advance showed unconsidered optimism. Neither is a recipe for victory in this long siege. (© Daily Telegraph, London)