A bomb in a graveyard in northern Afghanistan killed a parliamentary candidate and a retired policeman and wounded five, including a mayor, on Tuesday, an intelligence official said.
The attack happened in the Khan Abad district of northern Kunduz province as the men prayed inside the graveyard to mark the start of the Muslim Eid al Adha holiday, provincial intelligence chief Abdul Rahman Aqtash said.
Violence in Afghanistan was already at its worst since the Taliban were overthrown by U.S.-backed Afghan forces in late 2001 but a dramatic increase in attacks in the past few days will be a sobering message for NATO leaders ahead of a summit this week.
Mohammad Islam Mujahid, a candidate from Kunduz in Afghanistan's September parliamentary election, and Haji Bismillah, a retired police official, were killed in the attack, Aqtash said.
Bismillah was the brother of the mayor of Kunduz city.
The mayor, who had been praying with the other men, was wounded along with four civilians, Aqtash said, adding the bomb had been placed near the grave before the men had arrived.
Tuesday marks the first day of Eid al Adha. Afghans traditionally visit the graves of loved ones to offer prayers.
It was not immediately clear whether the attack was carried out by Taliban insurgents or by election rivals.
Once relatively peaceful, northern Afghanistan has seen a spike in violence over the past year as insurgents move out of their strongholds in the south and east. Militants frequently use Kunduz as a springboard to launch attacks in surrounding areas.
The September 18 election for Afghanistan's lower house of parliament went ahead despite insurgent threats to disrupt it, although at least 17 people were killed on the day in poll-related violence.
Four candidates were also killed before polling day.
Final results have still not been announced nearly two months after the election amid serious fraud concerns and calls from hundreds of candidates for the election to be annulled. The election body has already tossed out a quarter of the votes.