Pakistani officials say a suspected U.S. drone strike in northwest Pakistan has killed at least five militants.

Officials say the attack happened early Tuesday in the mountainous South Waziristan tribal area close to the Afghanistan border.

The attack comes less than 12 hours after Pakistani officials reported that a suspected unmanned U.S. aircraft killed up to 12 militants in a compound in the nearby North Waziristan region.

On Monday, the outgoing head of the International Committee of the Red Cross delegation in Pakistan reported a significant increase in violence throughout Pakistan since the killing of former al-Qaida leader Osama bin Laden in a U.S. raid in Abbottabad on May 2.

Pascal Cuttat told VOA in Geneva that about 1 million people are currently displaced in Pakistan due to fighting in the tribal areas and in Khyber-Pakhtunkhwa and Baluchistan provinces along the Afghan border. Cuttat said the ethnic, political and religious divisions in Pakistan have become more complicated and instability has increased since bin Laden was killed.

He said another effect of the U.S. raid is an increased suspicion of foreigners in the country, including aid workers. He said this suspicion has made it more difficult for foreign workers to move around Pakistan.