KABUL, Afghanistan -- A suicide bomber wearing a military uniform killed six police officers Wednesday inside the heavily fortified Interior Ministry compound in the heart of Kabul, authorities said, the latest in a wave of violence as the Taliban threatens to disrupt Afghanistan's presidential election this weekend.
Interior Ministry spokesman Sediq Sediqqi said the death toll rose from four to six as investigators reached the site of the explosion.
The bomber walked through several checkpoints to reach the ministry gate before detonating his explosives. An Interior Ministry statement said the bomber was among other men in uniform entering the compound.
Within minutes of the blast, Taliban spokesman Zabihullah Mujahid claimed responsibility for the attack. It came soon after he issued a statement to journalists warning of more violence ahead of Saturday's presidential elections.
Witness Mohammad Karim, who was walking toward the gate to leave the compound, said he was blown back by the force of the blast. Police then rushed him and others into a safe room.
Baryalai, a police officer who only gave one name as is common among Afghans, said the blast occurred near a bank that is close to the entrance gate. Police officers collect their paychecks at the bank.
A corresponding statement released on websites by the Taliban warned citizens against participating in the elections, saying polling stations and electoral commission staff would all be legitimate targets for attacks.
The Interior Ministry primarily has responsibility for securing the elections. Several recent high-profile attacks also have threatened to undermine the results by scaring voters away. The Electoral Commission's own office in Kabul was attacked last week by militants carrying suicide vests and small arms.
Earlier Wednesday, an Afghan official said Taliban gunmen killed nine people, including a candidate running for a seat in the provincial council, who had been abducted in northern Afghanistan.
The governor of Sar-i-Pul province, Abdul Jabar Haqbeen, said authorities received word that the candidate, Hussain Nazari, and the others were killed overnight by their abductors. They were seized by the Taliban three days ago while traveling to the provincial capital.
Haqbeen says they recovered four bodies and one man who was wounded, while the five other bodies, including the candidate's, are in a remote area and have yet to be found.
Haqbeen says authorities were told that Nazari and two others were beheaded.