Thousands of fearful civilians - many on foot or donkey-pulled carts - streamed out of a conflict-ridden Pakistani valley on Sunday as authorities briefly lifted a curfew. The army said it had killed scores of militants in the latest fighting. Pakistan has urged residents of the Swat Valley to leave over the past week, while its warplanes have pounded the militant-held valley and surrounding areas in a US-backed operation the prime minister has called a "war of the country's survival." The army said Sunday afternoon that it had killed at least 180 suspected militants over the previous 24 hours. It said at least 140 bodies of alleged militants were discovered in Shangla, a district next to Swat where fighting appears to have greatly intensified. Advancing troops destroyed a militant training camp in Shangla's Banai Baba area and battled militants at a bridge in the Chamtalai area, it said. Reports that militants from Swat had filtered into Shangla came out well before the latest operation, but it also was possible more insurgents have headed there to escape the bombardments in the valley. In Swat, the main town of Mingora was relatively calm. But the army statement reported some 50 to 60 militants had died Sunday in various parts of the mountainous valley. Two soldiers died in the latest fighting, including one who succumbed to injuries suffered Friday, the army said. Military officials could not be reached immediately to reconcile varying figures in the statement, and the toll could not be confirmed independently. Hundreds of thousands of civilians have already fled the valley, seeking refuge with relatives or flooding relief clamps - adding a humanitarian crisis to the nuclear-armed nation's economic, political and other woes. Once the curfew was lifted early Sunday, more residents in Swat towns tried to get out any way they could - on motorbikes, animal-pulled carts, rickshaws or simply on foot. A ban on civilian vehicles entering the valley complicated the exodus for those without cars. "We are going out only with our clothes and a few things to eat on the long journey," said Rehmat Alam, a 40-year-old medical technician walking out of Mingora with 18 other relatives. "We just got out relying on God because there is no one else to help us." Some cursed the situation and condemned the Taliban, while others blamed Pakistani leaders for engaging in the offensive to please the US "Show our picture to your master America and get money from him," some taunted. Taliban fighters were visible in Mingora. Army helicopters briefly shelled two neighborhoods in the city, but overall the fighting was significantly less than in previous days. Officials said the curfew would be back on by late afternoon or early evening; there were conflicting reports about the exact time. By giving residents a chance to escape, the army may be signaling it is preparing an escalation in its offensive against the militants who began a violent campaign to take over Swat some two years ago. Pakistan's leaders launched the full-scale offensive Thursday to halt the spread of Taliban control in districts within 60 miles (100 kilometers) of the capital, Islamabad. The goal is to wrest Swat and neighboring districts from militants who also dominate the adjoining tribal belt along the Afghan frontier, where US officials say al-Qaida chief Osama bin Laden may be hiding. The international aid agency World Vision said its relief workers were finding "intolerable" conditions at some relief camps due to soaring temperatures, overcrowding, inadequate toilets and a lack of electricity. "Despite the coordinated efforts of the Pakistani authorities, World Vision and other aid agencies on the ground, we may not be able to meet the most basic needs of the refugees as quickly as they are arriving in the camps if it continues at this pace," said Jeff Hall, an official with the aid group. In the northwest district of Mardan, government official Khalid Umerzai said more than 100,000 displaced Pakistanis were expected Sunday, on top of 252,000 already there. "Vehicles loaded with people are coming down bumper-to-bumper from Swat, and we are expecting a huge crowd of people and organizing two more relief camps in Mardan and Takhtbai," he said. Prime Minister Yousuf Raza Gilani has directed millions of dollars to help the residents of the region where faith in the government is shaky, saying the army "can only be successful if there is support of the masses." Taliban militants who had their stronghold in Swat began moving into surrounding districts in recent weeks despite a peace deal in which the government agreed to their main demand to impose Islamic law in the region. US officials likened the deal to a surrender. Pakistani leaders said the agreement's expected collapse had opened the eyes of ordinary citizens to the extremist threat. The army says 12,000 to 15,000 troops in Swat face 4,000 to 5,000 militants, including small numbers of foreigners and hardened fighters from the South Waziristan tribal region. The army accused militants of causing civilian casualties with indiscriminate mortar fire. However, officials have given no details of civilian casualties, apparently for fear of a public outcry that could make it hard for the army to press ahead.