A suicide bomber blew himself up at a checkpoint in northwest Pakistan as officials were trying to rescue a peace deal to contain Islamic militants in the lawless border region.
The bomber targeted a security checkpoint in North Waziristan, killing three Pakistani soldiers and one civilian.
Tuesday's attack is the latest in a wave of deadly violence following the breakdown of a peace deal between the Pakistan government and pro-Taleban militants. More than 70 people have died in attacks by suspected militants over the past few days.
Pro-Taleban militants pulled out of the deal on Sunday after accusing the Pakistani government of violating it by deploying more troops in North Waziristan and launching attacks. Authorities are trying to save the deal, despite concerns by the United States that it has provided a safe haven for Islamic extremists.
In a separate development, investigators say they have detained at least two dozen people in a probe into a possible assassination attempt on President Pervez Musharraf on July 6. Shots were fired as his airplane took off from a military base near Islamabad.
Some information for this report was provided by AFP, AP and Reuters.