Rebels say time running out for Gadhafi as crisis mounts in Tripoli

Tripoli, Libya (CNN) -- Libyan rebels expressed fresh optimism that Moammar Gadhafi's reign is about to crumble as a deadline looms for Gadhafi loyalists to disarm or face assault.

"I think this thug, this killer knows that he has nowhere to go," said Ali Tarhouni, finance and oil minister for the opposition's National Transitional Council.

Tarhouni said he expects Gadhafi's four-decade rule to fall apart within a week.

"I really have no problem with waiting another week," he said Tuesday. "I've waited 42 years."

But Gadhafi's whereabouts are still unconfirmed, 11 days after opposition forces stormed the capital and later captured his Tripoli compound.

Rebels now have their sights set on the remaining bastions in Libya under Gadhafi's control, including his hometown of Sirte.

The rebel government issued an ultimatum Tuesday for tribal leaders in towns under the control of loyalists: Surrender or face attack on Saturday, after Eid al-Fitr festivities end.

While battles rage on between pro-Gadhafi and rebel forces, a humanitarian crisis in Tripoli mounts.

Sixty percent of Tripoli was without water or sanitation, U.N. Secretary-General Ban Ki-moon said Tuesday.

"I cannot overstate the urgency of this moment," he said. "Time is of the essence."

Ban said he hoped to have U.N. personnel on the ground "as quickly as possible."

The European Union said pro-Gadhafi forces closed water-pumping stations while fleeing the capital. The resulting disruption of the water supply in Tripoli is "a major issue," an EU spokeswoman said, adding that security concerns along the road to the stations made it impossible to predict when the flow could be restored.

The U.N. children's agency was gathering 5 million liters (1.3 million gallons) of water to ship to Tripoli.

And the United Nations' World Food Programme was sending 600 tons of food commodities -- wheat flour, pasta, vegetable oil and tomato paste -- for the Red Cross to distribute in Tripoli.

Elsewhere in the capital, a former Gadhafi family nanny has emerged as the marred face of brutality in the country.

Shwygar Mullah said Aline Gadhafi, the wife of Gadhafi's son Hannibal, poured boiling water on her.

Mullah said Aline lost her temper when her daughter wouldn't stop crying and Mullah refused to beat the child.

Mullah's scalp and face are now a grotesque mosaic of red wounds and scabs. Her chest, torso and legs are all mottled with scars -- some old, some still red, raw and weeping. As she spoke, clear liquid oozed from an open wound on her head.

"She took me to a bathroom. She tied my hands behind my back, and tied my feet. She taped my mouth, and she started pouring the boiling water on my head like this," Mullah said, imitating the vessel of scalding hot water being poured over her head.

Mullah is now being treated at a Tripoli hospital after a guard secretly brought her in.

While rebels continue searching for Moammar Gadhafi, a clue came from a 17-year-old who told Sky News he saw Gadhafi on Friday in a Tripoli compound belonging to Gadhafi's son Khamis. The teen said he had been working for the previous month as a guard for Khamis Gadhafi.

The ruler arrived and spoke with his son for 10 to 15 minutes, said the teen, Abdu Salam Ataher-Ali.

Friday's visit by Moammar Gadhafi came as rebels were seizing control of the capital and Gadhafi loyalists were preparing to flee, the teenager told a translator during an interview in a rebel compound.

During the visit, the leader's daughter, Aisha, arrived at the compound, where she and her father got into a convoy of vehicles and drove off, the teen told the translator. "He said one of the high-ranking soldiers come to us and we asked him, 'Where is Gadhafi going?' and he said, 'To Sabha,'" the teen said.

Sabha is a city in southwestern Libya and one of the loyalist strongholds.

Khamis Gadhafi then got into an armored Toyota Land Cruiser and drove toward the town of Bani Walid, the teen said. Bani Walid is a city in the Misrata district in the north. An armored Land Cruiser was among a number of vehicles that were destroyed later by NATO bombs along the road northward.

It was not clear whether Khamis died in that attack, though residents in Tripoli celebrated word that he was dead. A rebel commander said Khamis Gadhafi was buried in the area.

The teen said he had been persuaded to join Khamis Gadhafi's group when he was told that foreign forces were attacking the country, Sky News reported. CNN has not been able to verify the Sky News report.

A rebel military commander claimed Tuesday that at least 50,000 people have been killed in the Libyan conflict.

The number was calculated by adding death tolls reported in battle zones and accounts from agencies such as the Red Cross, said Hisham Abu Hajer, the Tripoli Brigades coordinator. But he did not divulge the data underlying the total and CNN cannot independently verify it.

After months of carnage on both sides of the battle lines, rebels say a peaceful resolution is possible.

Tarhouni, the TNC minister, said one of Gadhafi's sons -- he did not disclose who -- is trying to negotiate.

But "there is really nothing to negotiate," he said. "What we offered -- and are still offering -- is that (if) they surrender, they will be safe, they will be brought to court under international supervision, and that's basically the deal on the table. Take it or leave it."

CNN's Nic Robertson, Dan Rivers, Frederik Pleitgen and Arwa Damon contributed to this report