Taliban insurgents attacked the Independent Election Commission headquarters in Kabul on Saturday, staff and police said, in the their third big assault on the capital this week aimed at derailing the April 5 presidential election.
Four hours after the attack started, Afghan security forces were still battling to secure the area in the east of the city. Eight international UN staffers remained inside the besieged IEC building, a security source said.
Another security official said at least three suicide bombers have been killed. No further details on casualties were available.
It is the second IEC building this week to have been targeted by the Taliban, and the attack occurred less than 24 hours after militants stormed a guesthouse used by a US-based aid group. A child was killed in Friday's attack.
Kabul is on high alert ahead of the presidential vote that Taliban insurgents have threatened to derail with a campaign of bombings and assassinations.
Election commission staff heard an initial explosion at around midday on Saturday at the IEC headquarters, followed by gunfire and rockets.
"Four suicide bombers armed with light and heavy weapons have entered a building near the IEC headquarters and are shooting towards the IEC compound and at passers by," Mohammad Zahir, the Kabul police chief, told reporters near the site of the attack.
The IEC compound is close to the United Nations Office Complex in Afghanistan (UNOCA) and other international organisations. "I am here ... the attack is going on around the IEC compound," IEC spokesman Noor Mohammad Noor told Reuters by telephone from a safe-room inside the building.
He said that IEC personnel were safe and that Afghan security forces were in control of their building.
UN staff at the complex near the IEC buidling were instructed to take refuge in safe-rooms until further notice. The owner of the house being used to fire at the IEC building said that three guards were present at the time it was taken by the Taliban, who had disguised themselves as women in the traditional all-covering burqa. "I had three guards, two outside and one inside, but I don't know what is happening right now. The attackers were wearing women's burqas," said Haji Mohibullah.
Mohibullah's house was being used as an office by campaigners for presidential candidate Gul Agha Sherzai, according to the Afghan military. "Three suicide bombers have been killed and one is hiding in a bathroom, and he will be killed very soon," said Qadam Shah Shaheem, a military commander.
TENSIONS RISE IN KABUL
With a week to go before Afghanistan's presidential election, escalating violence across the country risks undermining the credibility of a vote meant to mark the first democratic transfer of power in Afghan history.
Afghans are voting for a successor to President Hamid Karzai, who is constitutionally barred from running for another term in office. The vote is seen as a major test by foreign donors who are hesitant about bankrolling the government after the bulk of NATO troops stationed in Afghanistan withdraw later this year.
The spate of attacks has rattled nerves in Kabul, and on Saturday at least one international airline cancelled a flight into the city, while some domestic flights were diverted.
On Friday, Afghan security forces battled with the militants for hours before taking control of the guesthouse. The aid workers all survived, some by hiding in their rooms. Insurgents have launched a wave of so-called "complex" attacks in the capital, involving an initial bombing followed by gunfire. Dozens have also been killed in other assaults around the country in recent weeks.
Last week, nine people including an AFP journalist and an election observer, were killed in an attack on a highly fortified hotel in the capital. The hotel attack prompted most foreign election monitoring missions to withdraw their international observers, further denting confidence in the outcome of the vote next Saturday. Taliban suicide bombers and gunmen attacked an election commission office in Kabul on Tuesday. Ten people were killed in the attack, including a provincial council candidate.
(Reporting by Jessica Donati and Mirwais Harooni; Editing by Jeremy Laurence)