Afghan officials have arrested three Pakistani men they say were plotting to assassinate the U.S. ambassador to Afghanistan. The arrests come just hours after the U.S. military announced that increasing numbers of foreign militants have entered Afghanistan, apparently to help Taleban insurgents fight the central government.
Afghan authorities said the three men were captured in eastern Laghman province on Sunday, one day before U.S. Ambassador Zalmay Khalilzad was due to make an official visit.
The Pakistani men were reportedly armed with rocket-propelled grenades and rifles when they were arrested.
The U.S. Embassy in Kabul said it could not immediately comment on the arrests.
The alleged assassination plot comes amid reports of increasing numbers of foreign extremists entering Afghanistan to support Taleban insurgents who oppose the U.S.-backed central government.
U.S. military spokesman Colonel James Yonts, speaking in Kabul Monday, said foreign groups have been responsible for recent attacks in Afghanistan.
"There does exist proof of outside influences here in Afghanistan trying to establish a base…," he said.
U.S. and Afghan officials also allege that Taleban rebels use the remote border areas of neighboring Pakistan to launch their attacks.
Pakistan has denied the allegations, and says it has deployed thousands of troops to prevent cross-border activity.
In the last few months, the Taleban-led insurgency in Afghanistan has intensified, as militants step up their efforts to block parliamentary elections set for September.
Coalition forces in the past two days have killed more than two dozen suspected Taleban insurgents in a series of clashes across the country.
On Sunday, U.S. and Afghan troops engaged a group of militants in southern Afghanistan after coming under small arms and rocket fire. U.S. aircraft and attack helicopters responded, and up to 20 rebels were killed.
Separate fighting Monday reportedly left at least another 18 insurgents dead.