Two bombs in Pakistan’s southwestern province of Balochistan have killed at least 28 people, officials said, with dozens more injured.

The twin blasts on Wednesday came a day before elections. The attacks targeted the election offices of political parties in the restive region.

The first attack, which killed 16 people, took place at the office of independent election candidate Asfandyar Khan Kakar in Pishin district near the border with Afghanistan, said Jan Achakzai, Balochistan’s caretaker information minister.

More than 20 people were reported wounded in the blast, and police said some were in critical condition.

The second explosion in Qilla Saifullah detonated near an office of Jamiat Ulema Islam (JUI), a religious party that has previously been the target of attacks.

At least 12 people were killed in that attack, Achakzai said. At least eight more were injured.

The blast in Pishin was the result of an improvised explosive device attached to a motorcycle, he added.

In response to the dual attacks, the foreign office said in a statement that its western border crossings with Iran and Afghanistan would close until Friday to ensure security during the election.