Two NATO Apache helicopters killed 30 insurgents on Pakistani soil after a rare manned pursuit across the border from eastern Afghanistan Saturday, NATO forces said, adding the insurgents had earlier attacked a remote Afghan security outpost in Khost province.

Later that day, two Kiowa helicopters returned to the area and killed another four, NATO-led International Security Assistance Forces (ISAF) said in a statement Sunday. ISAF was not immediately able to confirm whether the Kiowa helicopters had also crossed the border.

There was another possible border violation Monday, when six militants were killed in Pakistan's Kurram borderland agency, a Reuters reporter in the area said, but an ISAF spokesman said it was "near the border," rather than in Pakistan.

"We did have a helicopter ... engagement near the border, but our reporting does not indicate that the helicopters crossed the border," said Major Michael Johnson. "However we are still receiving reports from the field so we are still gathering data."

ISAF said in a statement issued late Sunday that the helicopters were following its rules of engagement when they crossed into Pakistan.

Reuters