PESHAWAR - Suspected Islamic militants blew up a bridge in northwest Pakistan on Tuesday, closing a crucial supply line for NATO troops in Afghanistan as officials said 50 extremists were killed in military operations.
The 100-foot (30-metre) iron bridge in the Khyber district, built on a culvert under the British Raj, was destroyed early in the morning and all traffic on the road came to a standstill, official Tariq Hayat told AFP.
A Pakistani security official said paramilitary forces were working to repair the bridge and resume traffic flow on the only route through the fabled but militant-infested Khyber pass into Afghanistan.
"The traffic will be restored by tomorrow at midday," said the official.
"Hundreds of vehicles are stuck up on both sides of the bridge," said local official Rahat Gul.
The bulk of supplies and equipment required by NATO and US-led forces battling a Taliban insurgency in Afghanistan is shipped through US ally Pakistan, which offers a shorter route than other neighbouring countries.
Australian Wing Commander Mark Larter, a spokesman for the NATO force in Afghanistan, played down the temporary closure.
"Our current logistics arrangements are sufficient to meet our needs," he told AFP.
NATO runs another land route, in the southwest from Quetta through Chaman and across the border at Spin Boldak, and airlifts supplies from Pakistan's southern port city of Karachi.
Land routes are frequently closed because of unrest and the US military has sought to find alternative ways into Afghanistan to safeguard supply lines.
Last month, US General David Petraeus said deals involving Central Asian states and Russia were in place to safeguard extra routes.
The United States says northwest Pakistan has become a safe haven for Al-Qaeda and Taliban militants who fled after the 2001 US-led invasion of neighbouring Afghanistan to regroup and launch attacks on foreign troops across the border.
Pakistan, under massive Western pressure to clamp down on extremists, has stepped up an offensive in an attempt to wrest back control of the Swat valley, also in the northwest, which locals say has fallen to the insurgents.
Security and intelligence officials said 15 militants were killed in military operations across the area on Tuesday, bringing to 50 the number of Islamists killed since Monday night.
Until two years ago, Swat was a jewel in the crown of Pakistani tourism, frequented by foreign and local holidaymakers escaping to the mountains for skiing in winter or more refreshing climes in the punishing heat of summer.
But the region descended into chaos after radical cleric Maulana Fazlullah embarked on a terrifying campaign to enforce a Taliban-style Sharia law, prompting thousands of people to flee and suffocating day-to-day life.
A Pakistani intelligence official based in the northwest city of Peshawar said four paramilitary and police officers were wounded in clashes with Taliban militants who surrounded a police station in Shamozai village.
Around 35 police were believed to be holed up in the small building.
"The firing is continuing. There are reports of casualties among the police but we do not have exact figures," a police spokesman said.
Local officials said around 20,000 civilians have fled Swat since last week.
"The Taliban are brutal but the security forces are also using excessive force in civilian areas. It is a hopeless situation," said Abid Kaleem, a grocery store owner who fled for Islamabad.
"I managed to leave with my wife and two children on Friday but there were many who were trapped when the army was shelling," said the 33-year-old.
More than 1,500 people have been killed in militant attacks across Pakistan in the past 19 months and more than 1,500 troops have been killed at the hands of extremists since 2002, after Islamabad joined the US "war on terror".