ISLAMABAD: A bomb blast killed two paramilitary troops Sunday in Pakistan's Khyber region, where security forces are pressing ahead with an offensive to secure a major supply route for foreign forces in Afghanistan.

Also in the northwest, a suicide bomber attempted to attack a security post in the Swat Valley but was killed before he could strike. The incident showed the region was still dangerous despite the recent arrests of five militant commanders there.

The bomb in the Mandiknas area of Khyber was targeting a security convoy and was detonated by remote control, said Sadiq Khan, an official at Khyber agency administrator office. Four people were wounded in the blast, he said.

Pakistan began its latest offensive in the Khyber tribal region on Sept. 1 and says it has killed more than 150 militants. The fighting has caused thousands of residents to flee.

Militants have frequently attacked trucks traveling through the Khyber pass carrying supplies to NATO and US troops in landlocked Afghanistan.

Pakistan is under intense U.S. pressure to crack down on al-Qaida and Taliban militants along the Afghan border.

In April, it launched a major offensive in the Swat Valley that succeeded in retaking much of it from Taliban control. On Friday, the army announced the capture of five top Taliban commanders from the Swat Valley, including spokesman Muslim Khan.

On Sunday, a suicide bomber attempted to attack a checkpoint close to a fuel station in the region, but security forces fired on his vehicle from a distance and it exploded, killing him, said Maj. Mohammad Mushtaq of the Swat media center.