Six Pakistani militants arrested last month were "brainwashed" by radical clerics near the Afghan border and had been plotting suicide attacks against military targets, an intelligence official said. Also on Saturday, the military claimed to have inflicted significant casualties on militants in fighting in the past few days in the border region, an insurgent stronghold where top al-Qaida and Taliban leaders are thought to find a haven. The battles took place near a military camp in Ladha in South Waziristan in recent days, said army spokesman Maj. Gen. Waheed Arshad. "The militants suffered heavy casualties, but we cannot give any specific number on their dead," he said, without giving further details. The six suspected militants, one of whom is a retired army major with alleged links to al-Qaida, were arrested in December in raids in different parts of eastern Punjab province. The arrests were only made public within the past week.