The attack on the government-run hotel happened at Malam Jabba, part of the Swat Valley where followers of Fazlullah signed a peace deal with government authorities in May after months of clashes.
"Miscreants set the resort on fire last night. The extent of damage is still not known and information is coming in," said Usman Shafi, general manager of the Pakistan Tourism Development Corporation (PTDC), which runs the hotel.
Residents said a large portion of the resort had been reduced to ashes and the militants also damaged chairlifts and a tower belonging to the meteorological department.
The hotel, located some 150 kilometres north of Islamabad at an altitude of 9,200 feet, had been closed for several months since unrest in the area had kept all tourists away.
Swat police chief Waqif Khan told AFP the ski facility had been torched at Malam Jabba and the police had registered a case against "unknown miscreants," a term officials use to describe local Taliban militants.
"The PTDC hotel has been set on fire by unknown miscreants. We don't know the details since there is no government control in that area," Khan said, adding that nearby buildings were also damaged.
Militants also torched three houses and shot dead two relatives of a local politician in the Matta district of Swat Valley, Khan said. A woman was killed in the fire at one of the houses, he said.
Witnesses said the houses belonged to local politician Muhammad Sher, a member of PML-Q.
The government signed a peace deal with the militants of Swat in May and agreed to gradually pull out troops and introduce an Islamic justice system, while the rebels had said they would halt attacks and surrender their arms.
The Pakistan army launched a major offensive in October to clear Swat of militants loyal to Maulana Fazlullah, a radical pro-Taliban cleric who led an uprising to enforce Sharia law in the valley.
Meanwhile, a police checkpost was blown up by unknown men in tehsil Barikot of Swat whereas a girls' middle school was also set ablaze.
According to a private TV channel, unknown persons blew up the police checkpost with explosives in tehsil Barikot of district Swat. The blast damaged the building, however no loss of life was reported.
In another incident, the miscreants set a girls' middle school on fire in Parai area.
Meanwhile, the local Taliban here disowned burning of the gigantic structure of PTDC Motel in ski resort Malam Jabba in Swat District and termed it work of hidden hands.
Spokesman of Swat Taliban Haji Muslim Khan in a telephonic talk with local journalists here Thursday said that solution to all problems laid in Nifaz-e-Shariat and setting up of Qazi Courts in the district. He outrightly rejected involvement of the local Taliban in setting ablaze the motel.
In response to a question regarding peace talks held in Peshawar with Frontier government negotiating team, Muslim Khan said both sides agreed to keep the accord intact. The meeting focused on three points i.e. release of the Taliban prisoners, abolition of checkposts and compensation to affectees of operations in Swat.
The government team in the talks consisted of Senior Minister Bashir Ahmed Bilour, Provincial Minister Wajid Ali Khan, MPA Dr Shamsher Ali Khan and Home Secretary Tipu Mohabbat Khan.
The Taliban were represented by Haji Muslim Khan, Mehmud Khan, Muhammad Nisar Khan, Maulana Muhammad Amin and Ali Bakht.