PESHAWAR, Mar 27 (AP/AFP): A suicide bomber demolished a mosque packed with hundreds of worshippers attending Friday prayers close the Afghan border, killing at least 48 people and injuring scores more, officials said.

The attack in the Khyber region was the bloodiest in Pakistan this year and came hours before President Barack Obama was due to unveil a revised strategy expected to emphasize the need to eradicate militant havens along the Pakistan-Afghan frontier.

A government official accused Islamist militants of carrying out the bombing in revenge for a recent offensive aimed in part at protecting the major supply route for NATO and U.S. troops in Afghanistan that passes in front of the mosque.

Meanwhile report Washington adds, President Barack Obama Friday vowed to wipe out terrorists from Pakistani safe havens, warning Al-Qaeda was plotting catastrophic new attacks, as he unveiled a sweeping new Afghan war strategy.

Obama warned that restive Pakistani border regions were the "most dangerous place in the world" for Americans and described Al-Qaeda as a "cancer" that could devour Pakistan, more than seven years after the September 11 attacks.

The strategy places stabilizing Pakistan at the center of the reframed US approach for fighting an unfinished and bloody battle against Al-Qaeda, which Obama said suffered neglect during a US diversion to Iraq.

The president also called on US allies to join a major new civilian effort to stabilize Afghanistan, and warned he would not turn a "blind eye" towards government corruption which he said undermined faith in its leaders.