WASHINGTON – U.S. officials say Pakistan has apparently tipped off militants at two more bomb-building factories in its tribal areas, giving the terror suspects time to flee, after U.S. intelligence shared the locations with the Pakistani government.

Those officials believe that Pakistan’s insistence on seeking local tribal elders’ permission before raiding the areas may have most directly contributed to the militants’ flight, though they also suspect low-level security officials may have tipped off the militants.

U.S. officials have pushed for Pakistan to keep the location of such targets secret before the operations, but the Pakistanis say their troops cannot enter the lawless regions without giving the locals notice.

All officials spoke on condition of anonymity to discuss matters of intelligence.

The latest incidents bring to a total of four bomb-making sites that the U.S. has shared with Pakistan, only to have the terrorist suspects flee before the Pakistani military arrived much later. The report does not bode well for attempts by both sides to mend relations after the U.S. raid May 2 that killed Osama bin Laden in Abbottabad, only 35 miles from the capital, Islamabad.