Pakistani security forces arrested seven al Qaeda suspects on Wednesday in connection with attacks on trucks taking military supplies through the Khyber Pass to Afghanistan.
Intelligence officials said they are believed to have planned the attacks.
The arrests were made in a raid on the house of an Afghan refugee on the outskirts of Peshawar, the capital of North West Frontier Province.
Those arrested included four Arabs and three Afghans.
Most supplies for military forces in Afghanistan are sent by truck through the Khyber Pass near Peshawar to eastern Afghanistan, but the route has been subject to attacks in recent months.
Pakistan has closed the route twice during that time.
The United States and NATO are looking for alternative routes.
Chief of the US Central Command General David Petraeus said in Islamabad that agreements have been reached with Russia and Central Asian states for transit routes into northern Afghanistan.