KABUL, Afghanistan - Seven people have been arrested over a suicide bombing that killed six NATO troops in Afghanistan last week, Afghan intelligence spokesman Saeed Ansari said Monday.
Five Americans - including a colonel and two lieutenant colonels - a Canadian colonel, and at least 12 Afghan civilians were killed in the blast on May 18.
The arrests took place last week, Ansari said. He said the people arrested were working for a Taliban "shadow governor," Daoud Surkha.
The militant Islamist movement has a system of "shadow governors" assigned to order operations in Afghan provinces.
Ansari told CNN Surkha was "across the border," presumably in Pakistan.
The suicide bombing last week occurred on a busy road near a NATO-led military convoy and a registration center for the Afghan Army.
The five U.S. soldiers were Col. John M. McHugh, 46, of New Jersey; Lt. Col. Paul R. Bartz, 43, of Wisconsin; Lt. Col. Thomas P. Belkofer, 44, of Ohio; Staff Sgt. Richard J. Tieman, 28, of Pennsylvania; and Spc. Joshua A. Tomlinson, 24, of Louisiana.
Canada's Ministry of National Defence named the Canadian soldier as Col. Geoff Parker of the Royal Canadian Regiment, 42, of Oakville, Ontario.
Local medical officials said at least 12 civilians were killed and 48 injured. The British Foreign Office put the civilian death toll at 19.
Five U.S. military vehicles were destroyed along with 13 civilian cars. One of the civilian cars was a bus filled with people, a spokesman said.
Zabiullah Mujahid, a Taliban spokesman, confirmed the operation and said the attacker was able to "destroy five foreign vehicles and damage one more."
The U.S. Embassy decried the attack, saying it demonstrates the Taliban's "callous disregard for the well-being of the Afghan people."
- CNN's Paula Hancocks contributed to this report.