American efforts to help the Afghan opposition gain ground against the Taliban before winter set in appeared to be fruitless Monday, as the Northern Alliance failed to take advantage of concentrated U.S. attacks on strategic positions along the northern border and near Kabul. 

Heavy bombing took place near Taloqan, along the Tajik border about 150 miles north of Kabul, and near the major western city of Mazar-e-Sharif, where a Northern Alliance ground offensive launched Sunday was reported to be faltering hours after it began. 

Both Mazar-e-Sharif and Taloqan are along the northern stretch of the main road which rings the central Afghan mountains, and are essential to alliance and Western resupply efforts from Uzbekistan and Tajikistan. Taloqan was the Northern Alliance's headquarters until the Taliban took it in Sept. 2000, forcing the alliance to withdraw to the more isolated town of Feyzabad. Mazar-e-Sharif fell to the Taliban in 1998. 

Northern Alliance spokesman Mohammed Abil said in a telephone interview that U.S. jets pounded Taliban positions to the east of Taloqan, and B-52 bombers hit three separate sites about 30 miles northeast of the town. Taliban diplomats in Islamabad, Pakistan, reported American air attacks Monday in the northern provinces of Samangan and Balkh against positions defending Mazar-e-Sharif. 

Two loud explosions were heard on the outskirts of Kabul around 5 a.m., as artillery and heavy machine-gun fire reverberated from Taliban posts in the hills surrounding the capital. Later in the morning, huge clouds of black smoke rose after two B-52s dropped a total of nearly 20 bombs on a Taliban base at Estarghech, north of the city. 

Several hundred rebels paraded near the front line about 25 miles north of Kabul, chanting "God is great" as U.S. bombs exploded on Taliban positions across the plain. 

The Taliban-affiliated, Pakistan-based Afghan Islamic Press reported fresh American airstrikes on Kandahar, the southern city where the Taliban began, after a four-day lull. The press agency also said U.S. helicopter gunships attacked Taliban positions near Kabul, but that could not be confirmed. 

Helicopter gunships were widely used by the Soviets against Afghan guerrillas during the 1980s, but there has been no independent confirmation that the U.S. has used them so far in this campaign. 

The Taliban-controlled Bakhtar News Agency claimed bombs killed 10 people and injured 15 others in a village outside Mazar-e-Sharif. Five people died and seven were wounded in a raid near Kandahar, it said. The Pentagon has repeatedly dismissed the Taliban's claims of widespread civilian casualties as lies. 

President Bush ordered the airstrikes Oct. 7 after the Taliban repeatedly refused to surrender Usama bin Laden, chief suspect in the Sept. 11 terrorist attacks on the World Trade Center and the Pentagon. 

Meanwhile, Pakistani President Gen. Pervez Musharraf — a key ally in the U.S.-led campaign — will meet with British Prime Minister Tony Blair in London on Thursday, Blair's office said. The meeting will come a day after Blair meets with Bush in Washington. 

In Islamabad, Taliban Ambassador Abdul Salam Zaeef said the U.S. bombing had driven thousands of people from their homes. He said the situation had been made worse because Pakistan will not allow refugees into its territory. He called on the United Nations "help the people of Afghanistan inside Afghan territory." 

"The Islamic Emirate of Afghanistan commits itself to cooperating with the United Nations operation in this respect to prevent any further problems," Zaeef said. 

The United Nations has been reluctant to operate inside Afghanistan because of security concerns and has been trying to persuade Pakistan to open its borders to more refugees who could be cared for on Pakistani soil. U.N. officials have also complained of Taliban fighters harassing aid workers and looting supplies. Zaeef said the only threat to U.N. operations in Afghanistan was American bombs. 

The Qatar-based Arabic satellite television news channel Al-Jazeera played a videotape by bin Laden Friday in which the exiled Saudi labeled the U.N. a Western puppet and said Arab member countries were no better than infidels. 

To aid the Northern Alliance, more U.S. special forces have entered Afghanistan in the last few days, Air Force Gen. Richard Myers, chairman of the Joint Chiefs of Staff, said on NBC's Meet the Press Sunday. 

U.S. military planners are concerned that opposition forces, who have promised a major offensive, will get bogged down with the onset of winter in the weeks ahead. Bad weather will soon make roads impassable, obstructing the resupply of front-line troops. 

Bad weather is believed to have caused the crash Friday night of a U.S. helicopter inside Afghanistan on a mission to rescue a sick soldier. The helicopter was identified as an MH-53, probably an Air Force "Pave Low" special forces troop carrier. 

Four crew members aboard the downed craft were injured, none critically, and were taken out by a second helicopter on the mission. The ill soldier was rescued Saturday. 

Defense Secretary Donald H. Rumsfeld, on a tour of front-line states in the war against terrorism, sought to dispel fears that the air campaign was failing to crack the Taliban's grip on Afghanistan. 

In Pakistan on Sunday, Rumsfeld said the Taliban are no longer "functioning as a government" and were "not making major military moves." 

On Monday, Rumsfeld was in India, where he said the military operation in Afghanistan was becoming more effective every day and would not take years to complete. 

U.S. officials, however, have said the campaign against terrorism is global and could last well after the eventual end of fighting in Afghanistan. 

The Associated Press contributed to this report