25 people have been killed in a suicide bombing outside of a polling station on Pakistan's election day

Syed Zargahm/Getty Images

• 25 people have been killed and at least 40 have been wounded in an explosion outside a polling station in Pakistan, the Associated Press reported, citing hospital officials.
• Pakistanis are heading to the polls for a historic presidential election which has seen a violent campaign over the last several months.

25 people have been killed and at least 40 wounded in an explosion outside a polling station in Pakistan, the Associated Press reported, citing hospital officials.

Pakistanis are heading to the polls for a historic presidential election which has seen a violent campaign over the last several months.

On Sunday, a candidate was killed in a suicide bombing on his way to a campaign event in northwest Pakistan. At least 160 people have died this month in political attacks.