The explosion took place in a customs office in Kandahar, seen as the birthplace of the Taliban, injuring two international troops and three other people, the International Security Assistance Force (ISAF) said.
The provincial police chief for Kandahar, Khan Mohammad Mujahid, had previously said an interpreter and an unspecified number of US soldiers had died in the attack.
However, ISAF said there were no fatalities among its troops. It announced separately that a coalition soldier had died in a bomb blast in southern Afghanistan Monday without giving further details, in line with its policy.
"A suicide bomber detonated an explosive device at the customs house in Kandahar city, Kandahar province today," ISAF said in a statement.
"One person, who was not an ISAF service member, was killed in the explosion. Five people were wounded, two of which were ISAF service members."
The blast happened a few metres from the main gate of the office as a US military convoy entered the compound, said Colonel Abdul Ghani, the official responsible for security there.
The Taliban claimed that "14 American soldiers including two of their translators" were killed in the "martyrdom-seeking attack", according to the SITE monitoring group, which quoted a communique posted on a Taliban website.
The insurgents are known to regularly exaggerate the casualties from their attacks.
It is the latest in a string of bloody incidents to hit Kandahar, the scene of a major anti-Taliban offensive by international troops and one of the most dangerous parts of Afghanistan.
Last month, the province`s deputy governor, Abdul Latif Ashna, was killed by a suicide bomber on a motorcycle who blew himself up shortly after the official left his home.
The area`s police chief has faced a series of attempts on his life and the deputy mayor of Kandahar city, Noor Ahmad Nazari, was killed in October, six months after his predecessor was assassinated.
Six foreign soldiers died in an insurgent bomb attack in Kandahar province in December.
There are around 140,000 international troops, two-thirds of them from the United States, in Afghanistan fighting the militant Islamist Taliban.
Foreign troops are due to start a limited, conditions-based withdrawal from July, and Afghan forces are scheduled to take over responsibility for security in 2014.
A total of 37 foreign troops have been killed so far this year in Afghanistan, according to the independent iCasualties.org website.
The figure stood at 711 for last year, the highest death toll since the 2001 US-led invasion which followed the September 11 attacks.
Human rights watchdog the Afghanistan Rights Monitor (ARM) says that more than 2,400 Afghan civilians died in the war last year.
That too is the highest death toll since 2001. ARM blamed the Taliban and other insurgents for more than 60 percent of the deaths.
Elsewhere in Afghanistan on Monday, a child was killed in Helmand province, which borders Kandahar, during an air strike by international forces targeting insurgents.
The International Security Assistance Force (ISAF) called the incident "deeply regrettable".
And in eastern Afghanistan, the governor of a district in Khost province which borders Pakistan was killed by unknown gunmen, police said.
Sayed Mohammad, the district chief in Baak, was assassinated while driving to work. (*)
Editor: Kunto Wibisono
Copyright © ANTARA 2011