DERA ISMAIL KHAN, Pakistan (AP) — Intelligence officials say a roadside bomb exploded as army troops were clearing a road in Pakistan's northwestern tribal region, killing two soldiers.

The officials say the bomb was detonated by remote control Sunday on the road connecting the villages of Sararogha and Janata in South Waziristan, a former stronghold of the Pakistani Taliban.

The officials spoke on condition of anonymity because they were not authorized to talk to the media.

The army launched a massive ground offensive in South Waziristan last year to rout the Pakistani Taliban from its most important sanctuary in the country. But periodic attacks have continued in the rugged, mountainous area near the Afghan border.