Rebels said they arrested dozens of militiamen loyal to Moamer Kadhafi in their eastern bastion but suffered a blow Monday in western Libya, losing a village at the foot of a key mountain range.
At least 63 people were rounded up in an ongoing bid to tighten security in the eastern city of Benghazi, following an hours-long battle with Kadhafi loyalists in the opposition stronghold.
But in western Libya, pro-Kadhafi forces wrested back control of the village of Josh at the foot of the strategic Nafusa mountains, AFP journalists at the scene said.
Josh had been emptied of its residents, the rebels said.
The rebels captured the village on Sunday but said they were forced to retreat to the east, half-way along the road to the town of Shakshuka, after several hours of fighting.
The Nafusa region has seen heavy fighting between rebels and forces loyal to Kadhafi since the insurgents launched a major offensive this month in a drive on the capital Tripoli.
An AFP correspondent in Tripoli, meanwhile, said at least eight powerful explosions rocked the eastern suburbs of the capital on Monday, sending up a plume of black smoke over the Tajura district.
In Benghazi, opposition forces patrolled the streets on Sunday night in a bid to track down more members of the pro-Kadhafi group, a rebel spokesman said, as shoppers stocked up for Ramadan, the Muslim holy month of fasting.
"We caught about 38 and later today more than 25," the spokesman, Mustafa al-Sagazly, told AFP late on Sunday.
"Some of them ran away and we are trying to catch them all over the city," he said. "We are arresting them."
The arrests came hot on the heels of a five-hour raid by the rebel-backed February 17 brigade on a Benghazi factory, leaving four rebels and five Kadhafi loyalists dead.
The fierce shootout erupted at around dawn on Sunday during a raid on the cell holed up inside a licence plate-making factory.
Rebel spokesman Mahmud Shammam said the group had been rounded up for its role in organising a prison break in Benghazi last week when about 300 prisoners escaped, including high ranking prisoners of war.
The rebels' National Transition Council vice chairman Abdel Hafiz Ghoga said "only a minority" of the prisoners remained at large and that they "posed no serious threat."
But the pro-Kadhafi cell was found in possession of explosives and had "plans to plant car bombs in Benghazi," according to Sagazly, deputy chief of the February 17 brigade.
He added the "very same group" -- the Katiba Yussef Shakir -- was suspected in last week's assassination of General Abdel Fatah Yunis, a right-hand man to Kadhafi before his defection to rebel ranks.
NTC member Ali Tarhuni has said that those who killed Yunis after he was summoned back to Benghazi from the front by the council for questioning over military issues were members of another shadowy group with suspected Islamist tendencies, Obaidah ibn al-Jarah.
Rebels have also promised a "surprise" in the strategic oil hub Brega where they say they exchanged fire on Monday with troops loyal to Kadhafi.
"We are in the suburbs of Brega and I can see its lights sparkling in the short distance. Expect a surprise," said Salabi.
Mohammed Zawawy, a spokesman for the Union of Revolutionary Forces in Ajdabiya, told AFP that rebels engaged a small band of pro-Kadhafi fighters in the outskirts of Brega on Monday, the first day of Ramadan.
France on Monday said it had given Libyan rebels 259 million dollars (181 million euros) in frozen funds that used to belong to Kadhafi's regime, while Germany said it expelled a senior diplomat loyal to Kadhafi.
Kadhafi, meanwhile, has sent an envoy to Caracas carrying a letter for his ally, Venezuelan President Hugo Chavez, the Latin American leader said on Monday, without revealing the contents.
"The envoy brought a letter for me. That is good, the world needs to know about this," said Chavez, who has consistently denounced the NATO strikes in Libya as a Western oil grab.
NATO said its warplanes carried out 49 strike sorties on Sunday, with hits concentrated in and around Zliten and Bir al-Ghanam. Strikes were also conducted in Tripoli, Brega and Waddan.