The Pakistani army is urging civilians to stay away from militants as security forces advance on a key Taliban stronghold.
Troops moved into the northwestern towns of Matta and Kanju Sunday, drawing closer to the Swat Valley's main town, Mingora, where thousands of insurgents are believed to be based.
Security officials say they have relaxed a curfew and are urging people to leave the towns. The army is also asking people to help troops identify militants, saying they will only be defeated when people rise up against them.
The military says it has killed 25 militants in the last 24 hours. Interior Minister Rehman Malik told reporters Sunday that 1,000 insurgents had been killed since the latest offensive began last month.
The numbers have not been independently verified, because the government is banning journalists from areas where fighting is taking place.
President Asif Ali Zardari says the Swat Valley offensive is part of a bigger mission.
He told Britain's Sunday Times newspaper that military action would follow in Waziristan, another militant stronghold on the Afghan border.
The United Nations Refugee Agency says the military operation has caused at least 1.1 million people to flee their homes in recent weeks.
The agency's high commissioner, Antonio Guterres, is calling for massive international support to help the displaced.
Some information for this report was provided by AFP, AP and Reuters.