KABUL, Afghanistan (CNN) -- A suicide car bombing exploded outside the NATO headquarters in Afghanistan early Saturday, killing seven people and injuring 91 just five days before the country holds presidential elections, an Interior Ministry spokesman said.
A car burns after the suicide blast outside NATO's Afghanistan headquarters.
The massive bomb detonated near the main gate of NATO's International Security Assistance Force (ISAF) headquarters. Among the wounded were several coalition service members, according to ISAF.
The Taliban has claimed responsibility for the attack, an ISAF spokesman told CNN.
Afghan President Hamid Karzai, the front-runner in the polls, condemned the bombing.
"The enemies of Afghanistan, through such attacks in the run-up to the elections, want to spread terror among people, but they must know that Afghans are fully aware of the value of the elections and will cast their votes for the sake of security and peace in their country," Karzai said in a statement.
But Ferishta, 21, who like many Afghans gives out only her first name, was deterred.
"After seeing today's events, I have no intention in voting," she said, wearing a blood-soaked shirt and connected to an intravenous drip. "If we are not at peace, why should we vote, who should we vote for?"
One witness at the scene told CNN the explosion left a huge crater and damaged a coalition forces' vehicle. Billowing smoke rose over the city.
"The sound was like a very loud door banging right next to my ear," said CNN's National Security Analyst Peter Bergen. Watch Bergen describe blast
The attack occurred at 8:30 in the morning as people were heading to work and was particularly disturbing given the beefed-up security in Kabul ahead of the August 20 presidential and provincial elections, only the second since the fall of the Taliban regime in 2001.
The area around the ISAF headquarters is heavily fortified with concrete blast barriers and extra security forces. Watch more on Saturday's explosion »
Security has been a key concern as Afghans prepare to go to the polls next week. The Taliban has vowed to disrupt the voting.
"This will make people living in Kabul perhaps think twice about going out in the next few days," Bergen said.
Earlier this week, Richard Holbrooke, the U.S. State Department's special representative for Afghanistan and Pakistan, said the Afghan elections were critical to quelling a resurgence of the Taliban.
"Holding an election in a wartime situation is always difficult," Holbrooke said. "Holding one when the enemy has said they're going to try to disrupt it makes it even more difficult."
Despite Saturday's attack, ISAF spokesman Lt. Col. Todd Vician told CNN that NATO-led forces in Afghanistan remain confident the elections will be credible.
"There is a very robust security system in place," he said.
This summer has been the bloodiest in Afghanistan since 2001, particularly in troubled Helmand province in southern Afghanistan. U.S., British and Afghan troops there have been fighting Taliban militants to help provide protection for the upcoming elections. Watch more on Afghan preparations for elections »
Kabul, however, had experienced relative calm in recent months. The last such attack in the Afghan capital was in January when a suicide bomb exploded near the German embassy. The Taliban also claimed responsibility for that incident.
CNN's Atia Abawi and Hugh Williams contributed to this report.