Balochistan: Unrest after Pakistan Rebel Death
An indefinite curfew is in place but outbreaks of violence have also been reported in other parts of Pakistan.
Bugti, 79, was killed in a gun battle near his mountain cave hideout, officials said.
He was a key figure in the struggle for greater political autonomy and share of Balochistan's gas and mineral wealth.
His death is a major blow to rebels operating in the region - but may risk inflaming opposition to the central government, say analysts.
As news of his death spread, several hundred students from the state-run Balochistan university took to the streets in protest.
Police had to fire into the air to disperse the rioters who attacked and set fire to cars and smashed windows.
Sporadic flare-ups of violence continued in Quetta on Sunday despite the imposition of an indefinite curfew.
There were reports of similar outbreaks across the region.
In Kalat, 150km (90 miles) south of Quetta, a government building was bombed and a telephone exchange set alight, police said. No casualties were reported.
Elsewhere in Balochistan, vehicles were damaged and roads blocked by protesters, AFP news agency reported.
And the violence spread to Pakistan's biggest city of Karachi, in neighbouring Sindh province, where ethnic Balochis burned tyres, another report said.
Bugti died when his mountain cave hideout, near Dera Bugti district, was tracked down and attacked by Pakistani ground forces and from the air with missiles from helicopter gunships.
More than two dozen of Bugti's supporters are believed to have died in the heavy fighting that followed, along with a similar number of security personnel.
Information Minister Mohammad Ali Durrani confirmed to Reuters news agency that Nawab Akbar Bugti had been killed, although there is no official confirmation that the rebel leader's body has been found.
Four provincial parties have vowed to continue the protests.
"The government has pushed Balochistan into a never-ending war," said Hasil Bizinjo, leader of one of the parties.
Balochistan is Pakistan's biggest province, and is said to be the richest in mineral resources. It is a major supplier of natural gas to the country.
But for decades, Baloch nationalists have accused the central government in Islamabad of depriving the province of its due.
Nawab Akbar Bugti - known to many as the Tiger of Balochistan - played a major role in the politics of the province for more than five decades, the BBC's Steve Jackson writes.
He was involved in earlier failed insurgencies in the 1950s, '60s and '70s but he also served in the federal government and was on occasion governor and chief minister of Balochistan.
The latest fighting between government forces and Mr Bugti's followers began after attacks by separatists on the gas infrastructure in the region.
In one of his last interviews - with the BBC's Urdu Service in July this year - Mr Bugti was asked why a peace deal between his tribes and the government had not been implemented.
"They say that I am intransigent, I don't listen to them, I don't bow before them," he said.
"They say that I should bow before them and salute them, and give up my weapons, and then everything will be all right."
His vision for Balochistan has never been achieved but the insurgency he led has been one of the biggest headaches for President Pervez Musharraf in recent years, our reporter writes.
The main question now is whether or not his death will provoke more violence from the separatists, he adds.