A suicide bomber blew himself up in a bank in the Pakistani capital, Islamabad, Monday, killing a security guard and wounding four other people.

Police say the attacker detonated his explosives after the security guard stopped him from entering the bank. It was the first such attack in Islamabad since December 2009, when a bomber attacked the headquarters of Pakistan's navy, killing one person.

Witnesses reported hearing a loud explosion, which shattered glass and badly damaged the bank and nearby vehicles.

No group has claimed responsibility, but the Pakistani Taliban has vowed attacks in retaliation for the raid by U.S. special forces that killed al-Qaida leader Osama bin Laden in the northern city of Abbottabad last month.

In other violence Monday, a roadside bomb killed three Pakistani soldiers and wounded four others in the Ladha area of South Waziristan – a known stronghold of Taliban and al-Qaida-linked militants in northwestern Pakistan.

Elsewhere in the northwest, local officials say a bomb blast in the Khyber tribal region destroyed at least four trucks carrying fuel for NATO forces in neighboring Afghanistan. The trucks were parked at the main border crossing in Torkham. There were no reports of casualties.

And in the capital of southwestern Baluchistan province, Quetta, a bomb planted on a bicycle wounded two people.

The attacks came Monday as U.S. Deputy Secretary of State Thomas Nides held talks with Pakistani officials in Islamabad. The two sides discussed economic and trade issues, as well as counterterrorism and regional stability.

Nides is the latest U.S. official to visit Pakistan in a bid to repair relations further strained following bin Laden's death.