A suicide bomber killed 30 people outside a bank near Pakistan's capital today, while the UN said spreading violence in the country had forced it to suspend long-term development work in the north west regions along the Afghan border.
Islamist insurgents have carried out numerous attacks in Pakistan in recent weeks, killing some 250 people in retaliation for an army offensive in the Pakistan Taliban stronghold of South Waziristan.
The bloodshed, some of which has targeted aid workers, has jeopardised Western goals of reducing extremism's allure by improving Pakistan's economy.
Today's explosion in Rawalpindi, a garrison city just a few miles from Islamabad, left bodies on the ground outside the bank and in a nearby hotel car park, witness Zahid Dara said.
The stricken area also lies close to the army's main headquarters.
"I was nearby and rushed toward the parking area," Mr Dara told Dunya television. "There were many people lying on the ground with bleeding wounds, and a motorcycle was on fire with one man under it."
The attacker rode a motorbike to the scene, and the 30 dead included military personnel, Rawalpindi police chief Rao Iqbal said. Some 45 others were wounded.
"The bodies were lying all over," said Ali Babar, a rescue official who was doing a refresher course at a nearby college and rushed to the scene to help. "This is a terrible thing. It is happening again and again."
Pakistan's president, prime minister and other top officials condemned the blast but vowed to continue the offensive in South Waziristan, an impoverished and underdeveloped tribal region next to Afghanistan where al Qaida is believed to have hideouts.
The US supports the operation because it believes South Waziristan is a safe haven for Islamist extremists involved in attacks on Western troops in Afghanistan.
Washington has also stepped up its efforts to use development aid in a broader battle against spreading militancy. The US government recently approved 7.5 billion dollars in aid over five years to improve Pakistan's economy, education and other non-military sectors.
The UN decision to suspend long-term development work in Pakistan's tribal areas and its North West Frontier Province could complicate Washington's goal.
The UN made its decision after losing 11 of its personnel in attacks in Pakistan this year, including last month's bombing of the World Food Programme's office in Islamabad which killed five people.
UN workers were also among the 11 killed in a June suicide bombing of the Pearl Continental Hotel in the main north west city of Peshawar, and a veteran UN official was shot dead while resisting kidnappers at a north west Pakistan refugee camp in July.
The world body will reduce the level of international staff in the country and confine its work to emergency, humanitarian relief, and security operations, and also "any other essential operations as advised by the Secretary-General," the organisation said in a statement.
The UN has been deeply involved in helping Pakistan deal with refugee crises which have occurred due to army offensives against militants in the north west.
UN spokeswoman Amena Kamaal told The Associated Press that the organisation was still determining which programmes would be suspended and how many workers would be withdrawn from the country. She said "long-term development" applied to programmes with a timeframe of more than five years.
Staff who remain in the country will be assigned additional security, she said.
"We have had 11 of our colleagues killed because of the security situation," Ms Kamaal said. "All of the decisions are being made in light of that."
Foreign Ministry spokesman Abdul Basit said Pakistan understood the UN's reasoning, but that he hoped the organisation would resume its development work after the military completed its operation in South Waziristan.
"We hope that our operation will come to an end soon and they will resume their normal operations," he said.