Three people were killed when two bombs targeting the offices of candidates running in this weekend's election exploded in north-west Pakistan, intelligence officials said.
They said 15 other people were injured in the blasts in Miran Shah, the main town in Pakistan's North Waziristan tribal area.
Militants have killed at least 130 people in attacks on candidates and party workers since the beginning of April in an attempt to hamper the vote.
It was unclear exactly which candidates were targeted in the latest attack since several have offices in the block where the explosions occurred.
No-one has claimed responsibility for the attack, but suspicion is likely to fall on the Pakistani Taliban.