At least 70 people have been killed in clashes in the Swat valley on Thursday, the Pakistani military said.
More than 100 people are said to have died in the past week.
Nadim Baba, Al Jazeera's correspondent in Islamabad, has said that fighters in the area of Khwaza Khela have captured 63 Pakistani soldiers after surrounding a military camp.
They said they had also seized a large ammunitions supply.
He said: "The fighters contacted Al Jazeera and are inviting local journalists ... to have a look at the ammunitions store."
The AFP news agency has reported that fighters paraded 48 people they said were soldiers.
One of the group who spoke to reporters said that fighters had surrounded their hill-top outpost.
He said: "We had exhausted our rations and ammunitions. We had no option but to surrender.
However, the claims of the fighters or the identity of the alleged captive troops have not been verified.Increased concern
"Musharraf has many enemies in his country and I believe with Bhutto as PM there would be more people supporting the goverment"
Howahr, Doha, Qatar
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Meanwhile, there are fears that a state of emergency will remain in Pakistan if supreme court judges rule against Musharraf's bid to lead for another five-year term.
Benazir Bhutto, the former prime minister, who flew to the United Arab Emirates on Thursday reportedly for a weeklong visit with family, abruptly changed her travel plans several times amid such concerns.
Meanwhile, Condoleezza Rice, the US secretary of state - when asked if she and George Bush, the US president, had directly advised Musharraf not to declare martial law - said she would not speculate on developments in Pakistan or divulge details of their conversations.
She said: "I think it would be quite obvious that the United States wouldn't be supportive of extraconstitutional means."
Clashes between government troops and fighters loyal to Maulana Fazlullah, a cleric trying to enforce Taliban-style rule, is another example of the expansion of Islamist movements challenging Musharraf's control in northwestern Pakistan near the Afghan border.