Rawalpindi, Pakistan (CNN) -- A suicide bomber killed at least 35 people Monday by detonating explosives outside a bank where people had lined up to pick up their monthly checks, police said.
The blast, in the Cannt area of the city, also wounded more than 65 others, said Imdad Ullah Bosal, a district coordination officer. Two women were among the dead, he said.
Meanwhile, another suicide bomber detonated his explosives at a police checkpoint in Lahore hours after the Rawalpindi attack, a police official told CNN.
The bombers, believed to be wearing suicide vests, blew themselves up as police inspected their vehicle at the Babu Sabu checkpoint, according to Lahore police chief Pervez Rethore. The blast injured at least 17 police and civilians, a local rescue services spokesman said. At least three people sustained serious injuries, Rethore said.
In recent weeks, Pakistan has been rocked relentlessly by a wave of attacks as Islamic militants retaliate against a military offensive to rout insurgents operating along its border with Afghanistan.
The worsening situation prompted the United Nations to announce Monday that it was pulling all non-emergency foreign staffers from the country's northwest.
Video: Hospital treats bomb victims
Video: Pakistan violence
Video: Pakistan blast
The scene of Monday's deadly explosion in Rawalpindi is about 18 miles (30 kilometers) from the capital city of Islamabad. It is a closely guarded city that is home to the country's military headquarters.
The Cannt area is short for cantonment, so called because of its proximity to the military offices. It is home to several travel agencies and mid-range hotels.
The bomber rode up to the front of the National Bank in a motorcycle or a bicycle, said Rawalpindi Police Chief Rao Muhammad Iqbal.
The impact of the bomb was so intense that residents a block away said they thought the blast took place where they were.
The explosion blew out windows in the three-story building and blackened its walls. Rescue workers in surgical masks picked through the rubble looking for survivors.
Iqbal Nisouwana, a driver, who rushed to the scene to help tend to the wounded said he saw five men in uniform among the wounded.
"Two soldiers were injured. I helped put them in the ambulance," Nisouwana said. "And I saw three more wounded."
"One old man called to me for help," he added. "I tried to pick him up but he was too heavy."
On October 10, militants held dozens of hostages for some 22 hours inside the army headquarters in Rawalpindi. Eleven military personnel, three civilians, and nine militants were killed in the siege.
On October 20, back-to-back explosions took place at Islamabad's International Islamic University. At least six people died in the attack. Twenty-nine others were wounded.
And on October 28, a massive car bomb tore through the heart of a bustling marketplace in Peshawar, killing at least 100 people and injuring at least 200 others.
The attack on the capital of the North West Frontier Province was the deadliest terrorist attack on Pakistan since the October 2007 attack on a homecoming rally for former Prime Minister Benazir Bhutto. More than 135 people were killed in the suicide bombing in Karachi. Bhutto escaped harm, but she was assassinated two months later.
Her husband, Asif Ali Zardari, is now the president of the country.
The U.N. decision to withdraw staffers applies to all except those needed for emergency, humanitarian and security operations in the North West Frontier Province and the Federally Administered Tribal Areas (FATA), said spokeswoman Ishrat Rizvi.
The agency has been providing aid to the 2 million Pakistanis who have been displaced in the fighting between government forces and Islamic militants.
This year, the United Nations has lost several staffers to terror attacks, including five who were killed in a suicide bombing at the World Food Programme offices in Islamabad last month.
Two more U.N. workers died when attackers shot their way onto the grounds of the Pearl-Continental Hotel in Peshawar in June and set off a car bomb.
And gunmen killed a U.N. worker during a kidnapping attempt in Peshawar in July.
CNN's Ivan Watson in Rawalpindi, Samson Desta in Islamabad and journalist Nasir Habib contributed to this report.
