The rebels had fought their way in through the narrow streets and alleyways when they ran into an ambush. A desperate appeal for help to their comrades, exiles from Bani Walid whose advice they had followed on the assault, was answered by instructions to fall back to a rendezvous point outside the town.
But when the revolutionaries reached their destination, having fought their way out under intense fire, there was no sign of the Bani Walid contingent. Then, as urgent attempts were being made to establish communications, came salvos of mortar rounds and rockets.
By the time the opposition fighters had brought their casualties, five dead and 18 injured, to the nearest medical facility, they were enraged, accusing the Bani Walid men of betrayal. And some of the "outside" groups returned to Tripoli in disgust.
"We were given directions by the Bani Walid men we were leading and they were supposed to be behind us," said Ahmed Ishmail Jawad, a 24-year-old student and volunteer. "We faced a lot of fighting, much more than we expected. When we called for reinforcements, there was no one. We were told to get back and arrange another attack with the Bani Walid men. But they had gone back further and we had Grads [rockets] coming on us."
His companion from Zintan, Nasr Hamid Husseini, added: "There is something going wrong here. We cannot have success if people are going in different directions. We are worried about the loyalties of some of these men."
Mohammed el Ghadi, from Khoms, believed that tribal loyalties had superseded those of the revolution. "They are all Warfalla, those inside Bani Walid and those with us. We believe there are traitors among them."
The friction among those attempting to take Bani Walid, one of three remaining areas, along with Sirte and Sabbah, in regime hands, was the most incendiary sign of the increasing schism in the ranks of the opposition which has begun to appear within weeks of Muammar Gaddafi's overthrow.
Before Sunday night there had already been discord, with groups of local fighters demanding that certain areas within the town should not be attacked because members of their clans were there. Fighters from other parts have claimed, however, that they had received incoming fire from some of those areas.
The most potent sign of the divisions in rebel ranks in the past was the assassination of the commander Abdul Fatah Yunis, supposedly by Islamists in the ranks of the rebel forces he commanded.
The level these tensions have since reached were illustrated by a press conference the caretaker Prime Minister, Mahmoud Jibril, was due to hold on Sunday night at the Radisson hotel in Tripoli, being used as a base by the rebels' Transitional National Council (TNC). This was twice postponed and then had to be moved to another venue.
A senior member of the Tripoli Military Council, and spokesman for Abdelhakim Belhaj, the commander of forces in the Libyan capital, was blunt: "Jibril represents no one. He is not welcome here. We have just fought to get rid of one dictator, we don't want another one."
The antipathy towards the unelected members of the TNC forming the new administration is increasingly widespread and vocal. Most of them are former members of the Gaddafi regime, viewed as opportunistic converts from the old order. There is also the charge that some of them have been in Europe, the US and the Gulf states while young volunteers had been dying in the cause of the revolution.
Abdulbasit Abu Muzairik, a senior member of the council of Misrata, the port city which withstood a siege from Gaddafi forces, expressed what he said was widespread frustration. "We are worried about a lot of things which are happening politically. We have not seen Jibril in Libya, he has spent all the time we were suffering outside the country. Suddenly he is here and we have to accept he is the Prime Minister.
"What are people trying to do about it? Well, he will have to be replaced. We are looking at ways this can be done. The people who actually fought for the revolution must be allowed to have a say in how the country is now being run."
Mr Belhaj, who, The Independent revealed, was subject to rendition and torture with the help of British intelligence, has been the focus of media attention. Mr Muzairik pointed out that Mr Belhaj, a former head of the LIFG (Libyan Islamist fighting Group), "is just in charge of fighters in Tripoli, that's all. He is not in charge of Libya, even if he thinks he is."
So far, Mustapah Abdul Jalil, head of the TNC, has escaped criticism. But he has his own concerns about the future. The former Justice Minister under Col Gaddafi has warned of the existence of "extremist fundamentalists within the ranks of the revolution" and threatened to resign unless they, and other armed groups, handed in their weapons.
Abdurrahman Shalgham, an ally of Mr Jalil who was Foreign Minister in the Gaddafi regime, focused on the role of Mr Belhaj and his conservative Muslim followers, maintaining that he was "just a preacher and not a military commander". Another TNC member, Othman Ben Sassi, insisted: "He [Belhaj] was nothing, nothing. He arrived at the last moment and organised some people."
But there has been little sign of organisation on the Bani Walid frontline. One TNC officer, Mohammed el-Fassi, said yesterday: "The problem is that now that Gaddafi has fled, people are just thinking about themselves, their tribes, their own cities. They are not thinking about Libya."