A gas cylinder exploded on the top floor of a Pakistani hotel in Islamabad late Thursday, injuring three women and a child in a city always on guard against feared terror attacks, police said.

The blast struck the Citi Hotel in the Blue Area, the Pakistani capital's ordinarily bustling district of shops and restaurants around 11 pm (1800 GMT) at a time when people still linger over dinner in the cool breeze of evening.

The skirl of bagpipes may conjure up the chilly moors of Scotland, but a British colonial legacy means the unique sound is echoed on Pakistan's dusty Punjab plains.

Not only do Pakistanis play the instruments, they manufacture them and claim to export more than any country except Scotland.

A suicide bomber struck a public meeting in Pakistan's northwest on Monday where a cabinet minister had been due to speak, killing six people including a child.

Amir Muqam, minister without portfolio from the Pakistan Muslim League-Q party, had not yet arrived at the venue when the bomb exploded in a town near the Swat valley, where the Taliban once led a two-year insurgency.

Pakistani troops backed by attack helicopters clashed with Taliban fighters in the main town of the notorious North Waziristan tribal district, witnesses and officials said.

The rare clashes came one day after a bomb killed three Pakistani soldiers and although military officials confirmed troops were in action, there was no sign it was the start of a major offensive, long demanded by the Americans.

Pakistan is decorating bus stops with Koranic verses and Islamic calligraphy to give a more spiritual flavor to the capital Islamabad, long considered one of the country's most liberal cities.

The Capital Development Authority (CDA) plans to roll out 100 new bus shelters -- known locally as sunshades -- painted with flowers and religious verses to spruce up the 1960s purpose-built capital.

Pakistani war planes pounded a militant stronghold in a tribal district on the Afghan border in an operation that left 25 insurgents dead, the military said Sunday.

Pakistan army, paramilitary troops and the air force launched a joint operation "to evict terrorists' stronghold of Walidad" in the northwest district of Mohmand on Saturday, it said.

Pakistan's top military spy agency has arrested five Pakistani informants who assisted the CIA ahead of the raid that killed Osama bin Laden, The New York Times reported Wednesday.

The arrests of the men, including a Pakistani Army major said to have copied the license plate of cars that drove up to bin Laden's compound deep in Pakistan, comes amid strained ties between Washington and Islamabad in the wake of the U.S. Navy SEALs raid last month.

A bomber blew himself up in an Islamabad bank on Monday, killing a security guard in the first suicide attack in the Pakistani capital for nearly two years.

The attack comes with Pakistan on edge weeks after U.S. Navy SEALs found and killed Osama bin Laden in the garrison city of Abbottabad, two hours' drive from Islamabad, in a case that humiliated the seemingly all-powerful military.