Pakistan earlier this month signed a deal with pro-Taleban militants in its North Waziristan province, aimed at reducing militant raids into Eastern Afghanistan. But U.S. officials report a sharp rise in violence in that same part of Afghanistan.
The deal, signed three weeks ago, was presented as a major breakthrough in Pakistan's efforts to reinforce security along the Pakistan-Afghan border.
But U.S. military officials say extremist attacks in eastern Afghanistan have tripled since the peace deal was signed September 5.
Colonel Jon Paradis, a U.S. military spokesman in Afghanistan, says the fighting is particularly strong just across the border from Pakistan's volatile tribal areas of North Waziristan.
"There has been an increase in activity, certainly along the border region, especially in the southeast areas across from North Waziristan," said Paradis. "They have seen, in some cases, two-fold, in some cases, three-fold increases in the number of attacks."
Paradis says the violence stems at least in part from stepped-up U.S. military operations in the area. U.S. officials are declining to comment on any direct links between the latest attacks and Islamabad's agreement with North Waziristan.
Under that agreement, the government promised to withdraw most of its troops from the region. In exchange, tribal leaders agreed to expel foreign extremists and help end cross-border raids.
Pakistani officials hailed the agreement as a significant step toward peace in the volatile region. But Afghan officials and local security experts say the deal effectively cedes control of the tribal areas to religious extremists, including pro-Taleban militants.
Pakistan President Pervez Musharraf has rejected those concerns, defending the accord last week during a joint press conference with U.S. President George W. Bush at the White House.
"This deal is not at all with the Taleban, as I said, this is against the Taleban, actually. This deal is with the tribal elders of North Waziristan agency," he said. "And when they signed the deal, they are honor-bound to not only abide by it, but also that whoever violates it, they will move against them."
Pakistani officials say militant attacks against government forces in North Waziristan have dropped significantly since the accord was signed. But authorities say militants have murdered at least three men in the same period after accusing them of being U.S. spies.
Border security remains a major source of tension between Pakistan and Afghanistan.
Afghan President Hamid Karzai has repeatedly accused Islamabad of allowing Taleban insurgents to establish safe havens inside the Pakistani tribal agencies.
President Bush this week pressed both sides to improve coordination on regional security.