TRIPOLI, Libya, Aug. 25 (UPI) -- The NATO military alliance joined in the search for Libyan leader Moammar Gadhafi after rebels encountered resistance from his supporters, officials said.
British Defense Secretary Liam Fox said Thursday he could "confirm that NATO is providing intelligence and reconnaissance assets [to rebels] to help them track down Colonel Gadhafi and other remnants of the regime," Sky News reported.
Rebel forces said they were closing in on one of Gadhafi's few areas of support in his hometown of Sirte and that fighters had begun battling for Sabha and Zuwarah, The New York Times reported Thursday.
Adding to the pressure on the embattled leader -- whose whereabouts since his compound was overrun by rebels Tuesday are unknown -- is a reward reported as either $1.4 million or $1.7 million offered for his capture dead or alive.
"We fear a catastrophe because of his behavior," rebel leader Mustafa Abdel Jalil said.
Fox didn't comment on an account in The Daily Telegraph that British special forces were involved in the search for Gadhafi. He said there were "absolutely no plans" to commit British ground forces to Libya.
On the diplomatic front, the rebels encountered a setback after South Africa refused to endorse a U.S. attempt before the U.N. Security Council to release $1.7 billion in frozen Libyan funds for the rebels.
Fox ripped South Africa, saying: "I think there will be huge moral pressure on South Africa. They wanted the world at one point to stand with them against apartheid. They now need to stand with the Libyan people."
British Foreign Secretary William Hague said South Africa agreed to support release of $500 million for humanitarian purposes after British Prime Minister David Cameron called South African President Jacob Zuma.
In Tripoli, a ship sent by the International Organization for Migration to ferry migrant workers to safety finally docked Thursday after days of waiting offshore, the Times reported. It wasn't clear whether the port was secure enough for the migrants to reach the ship, Jemini Pandya, an organization spokeswoman said.
If the evacuation occurs, it would be the first organized evacuation from Tripoli since governments sent ships and planes to help foreigners leave when the Libyan crisis erupted in February.
Witnesses told CNN fighting between rebels and Gadhafi supporters erupted Thursday at the embattled leader's compound, scene of several clashes in recent days.
Smoke rose from the compound two days after rebels seized control of it in a fierce firefight, CNN reported.
"I think there is a lot of ammunition inside and it may have exploded," Abu Hajer said, referring to smoke in the compound. "There are four floors of ammunition under the ground and there are lots of old tires and cars so it may have exploded."
On Wednesday, Gadhafi taunted the rebels in an audio message and urged loyalists to rise up in Tripoli.
"I have been out a bit in Tripoli discreetly, without being seen by people, and ... I did not feel that Tripoli was in danger," Gadhafi said in the message broadcast by two Arabic-language networks.
CNN said it couldn't independently authenticate the recording.
Nearly all the hospitals in Tripoli were receiving wounded, "but some of the hospitals have not been accessible due to the fighting, which means that other hospitals have an added burden," said Jonathan Whittall, head of the Doctors without Borders humanitarian mission in Libya.
Two surgical teams were en route from Europe, with the first set to arrive Friday, said Robin Waudo, a spokesman for the International Committee of the Red Cross.
Fighting between rebels and Gadhafi loyalists erupted Wednesday outside the Rixos Hotel, where 35 international journalists and foreign nationals were released after being held for five days by Gadhafi forces.
Four Italian journalists kidnapped in Tripoli were released Thursday, the Italian Foreign Ministry confirmed.
In Brega, several crude oil storage tanks have been afire for six days since they were torched by retreating troops, said Ramadan Shalash, the refinery fire chief.