Pakistani security forces have seized several key areas in the main town of the Swat valley, as part of a continuing operation against Taliban fighters in the country's northwest, the military has said.
Military officials on Sunday said troops were in control of several main intersections and three main squares in Mingora, the AFP news agency reported.
Pakistani troops entered the town a day earlier, engaging in street battles with the Taliban and killing at least 17 fighters, Major-General Athar Abbas, a military spokesman, said.
"We have blocked all the entries and exits [in Mingora]," Abbas told Al Jazeera.
"Now the forces that were already present inside have linked up with the outside forces, and with this increased ratio they are moving from one end to the other.
"It will take more time."
Al Jazeera's Imran Khan, reporting from the Pakistani capital, Islamabad, said that the urban battles being fought by the Pakistani infantry marked a new phase in the conflict in the North West Frontier Province (NWFP).
"The army is telling us that street fighting will be one of the key phases of this battle for Mingora; so far they have used heavy artillery and air power to pound Taliban targets," he said.
"But the Taliban know this area very well and it is likely they will have been preparing for this moment for some time. It is likely they will have built tunnels and will know exactly what rooftops to get on."
Mingora, the administrative and business hub of Swat in the NWFP province has been under the effective control of Taliban fighters for weeks.
There are reports that Mullah Fazlullah, one of the leaders of the Pakistani Taliban, is in the town.
Many of the 300,000 people who live in Mingora are believed to have fled since the military began its offensive in Swat, Lower Dir and Buner districts of the NWFP several weeks ago.
Abbas told Al Jazeera the troops are slowly advancing through Mingora to avoid casualties among any civilians in the town.
"We have to go deliberately, avoiding the civilian casualties, taking every house - first clearing it, then moving forward. The uncertainty is there because [the Taliban] can come up from any house, any rooftop."
Military commanders have stressed that they are under orders to avoid collateral damage and avoid using heavy weaponry in built-up areas.
But Al Jazeera's Mike Hanna, who travelled to the war zone with the Pakistani military, said on Sunday that conditions for residents still in Mingora are getting "desperate".
"The situation in Mingora is compounded by the fact that by the army's own action in taking the town, at the same time the civilians are being cut off," he said.
Many of the displaced are staying in the homes of friends, families or complete strangers, putting a massive strain on people who were previously untouched by the conflict, he said.
The offensive in Swat and surrounding areas in the NWFP has triggered an exodus of nearly two million refugees from the region.
Meanwhile, Yousuf Raza Gilani, Pakistan's prime minister, has played down the suggestion of Asif Ali Zardari, the country's president, that the military offensive could be extended to the semi-autonomous South Waziristan region.
"It is not like this," Gilani said in response to a reporter's question about a possible new front. "We are not foolish to do it everywhere."