KABUL, Afghanistan — The number of insurgents reported killed in a NATO attack on a large encampment in a remote area of Paktika Province rose to 80 on Saturday, said Afghan officials, adding that they were concerned that there could be more undetected militant camps within the country’s borders.

The camp, which was raided Thursday by NATO troops backed up by Afghan forces, accommodated considerably more people than most compounds where Taliban and other insurgents take shelter along the border with Pakistan. The discovery raised questions about how entrenched the insurgency had become in southeastern Afghanistan. NATO has conducted many raids along the border, but rarely if ever come across compounds big enough for dozens of insurgents, officials said.

Most of the dead were from the tribal areas of Pakistan, NATO and local officials said. The tribal areas on the Pakistan side of the border are populated by Pashtuns of similar background to those on the Afghan side and are home to many Afghans who fled their country during the Russian occupation here.

A NATO spokesman declined to give any information on how many of the insurgents were Pashtuns from Pakistan and how many were foreign jihadi fighters. Foreign fighters, mostly from the Arab world or central Asia, are frequently associated with Al Qaeda and similar groups dedicated to global jihad.