Taliban gunmen stormed a Kabul guesthouse used by a U.S.-based aid group and held four foreigners hostage for several hours on Friday, just eight days before Afghanistan holds a presidential election which the militant group has vowed to derail, according to the Associated Press.

Kabul is already on high alert and people across the country are on edge ahead of an April 5 vote the hardline Islamist movement has denounced as a Western-backed sham, the AP reported.

The siege of the walled compound, which is also home to a small church, lasted several hours before Afghan security forces killed the last remaining Taliban gunman holed up inside, according to the AP.

At least one Afghan child was killed when a suicide bomber blew himself up outside the building and the insurgents forced their way in. There were no foreign casualties, the AP reported.

The country manager of an organization using the guesthouse said four people had been held hostage by the Taliban as their colleagues made frantic phone calls to establish whether they were alive, according to the AP.

"I can confirm it was attacked and that there are only four people" inside, said Hajji Mohammad Sharif Osmani, country manager of Roots of Peace, a U.S.-based group involved in demining and other projects in Afghanistan, the AP reported. "The rest of the guys are outside."

Marie Harf, a spokeswoman for the U.S. State Department, said there had been two U.S. citizens in the guesthouse, and both were safe, according to the AP. She said she did not know if they had been among those held hostage.

"We condemn this attack on Roots of Peace ... an organization that only seeks to help Afghans improve their lives and their livelihoods," Harf told a regular news briefing in Washington, adding that the organization is supported by the U.S. government, the AP reported.

"Again, the Taliban's actions demonstrate the growing distance between them and the Afghan people," Harf said, according to the AP. "A large majority of Afghans reject what the Taliban is trying to sell them. They reject this kind of violence and fear and intimidation and want to go to the polls."