A suicide car bomber rammed his explosives-laden car into the gates of a NATO base and airport in the northeastern Afghan city of Jalalabad Monday, killing nine people and wounding 12 others.

The Taliban claimed responsibility, saying it was the latest act of revenge for the burning of Qurans at the Bagram Air Base north of Kabul.

The commander of U.S. and NATO forces in Afghanistan, General John Allen, joined Afghan President Hamid Karzai in condemning the bombing in Nangarhar province. Mr. Karzai called the attack “inhuman and unIslamic.” No NATO troops were among the casualties.

This attack followed six days of deadly protests over the handling of Islam's holy books. Close to 40 people, including four U.S. military personnel, have died in nearly a week of protests since the incident.

In other news Monday, the United Nations announced it is pulling its international staff from an office in northern Kunduz province after it came under attack from protesters on Saturday.

The U.N. said the staff will be relocated within Afghanistan and that additional arrangements and measures will be put in place to “ensure the office can continue to operate in safety.”

Also Monday, the Taliban claimed an Afghan cook working on their behalf poisoned the food at a NATO base in eastern Afghanistan. A NATO spokesman said traces of bleach were found in food at a dining facility, but it was unclear if the food was tainted intentionally. The spokesman said no one got sick.

The U.S. Embassy has been in lockdown since the violent demonstrations erupted last week. It has warned of a “heightened” threat to Americans in Afghanistan.

On Sunday, the U.S. ambassador to Kabul, Ryan Crocker, told CNN that tensions are running very high, but that Washington should not withdraw troops ahead of schedule. Under an international agreement, foreign combat forces are to leave Afghanistan by the end of 2014.

Observers say the deteriorating security situation also could add pressure on NATO allies in Europe to accelerate plans to leave Afghanistan. The bloody and expensive war is already deeply unpopular.

The Afghan defense and interior ministers have postponed scheduled trips to the United States this week so they can remain in Afghanistan to monitor the situation.