The Lebanese army began operations against Fatah al-Islam in May in the wake of an attack on soldiers in Tripoli.
Security sources told Reuters news agency that some of the explosions on Friday were caused by soldiers blowing up booby-trapped buildings and mines.
Murr said many of the remaining fighters had withdrawn to civilian areas deep inside Nahr al-Bared and the army would continue its siege until they gave themselves up.
"The Palestinian refugees are not being treated properly by Lebanon"
Send us your views
He said Shaker al-Abssi, Fatah al-Islam's leader, was unaccounted for, along with his deputy Abu Hureira.
"It's not good enough to say Abssi was killed. If he is dead, give us the body."
Zeina Khodr, Al Jazeera's correspondent in Lebanon, reporting from the camp said: "From where we are standing we are not hearing any resistance, it is just the Lebanese army pounding positions and detonating bombs.
"It is very early to say that this is a victory, very early to say that this crisis is over."
Khdor said for five weeks the Lebanese army, observing a decades-old deal that prevents the army from entering Palestinian refugee camps, had concentrated its fire on the outskirts, in the 'new camp', where Fatah al-Islam had its bases.
The 'old sector', an area the army has not entered, is believed to be under control of mainstream Palestinian groups and where hundreds of trapped civilians have been taking shelter, she said.
Elias Hanna, a retired Lebanese army general, said until Fatah al-Islam is totally defeated, the situation will not be completely stable.
"I don't think there are any taboos preventing the military from entering the area.
"The military objectives have not totally been achieved. Military objectives will only be achieved when Shaker al-Abssi is killed or delivered to the Lebanese army."
Mohammed al-Hajj, spokesman for a group of Palestinian religious leaders negotiating a truce, said that Fatah al-Islam had said it would respect a ceasefire.
"I have been in contact with their spokesman Shahin Shahin, and they are ready to respect a truce," he said.
Fighting soon moved to Nahr al-Bared, home to at least 30,000 Palestinian refugees.
Thousands of civilians in the camp fled amid fierce fighting between the army and Fatah al-Islam fighters entrenched in the camp.
At least 75 soldiers and 60 Fatah al-Islam fighters, as well as 20 civilians, are understood to have been killed in the weeks of fighting.
Source: Al Jazeera and agencies