Italian troops in eastern Afghanistan say they have come under attack from unidentified gunmen.
About 500 Italians are based at Camp Salerno
Correspondents say it is the first serious incident since they took over the Salerno military base from US troops last Saturday.
An Italian spokesman said the attack began when troops came under rocket fire.
A few hours later a nearby US airbase also came under attack.
Camp Salerno is in the province of Khost, close to the border with Pakistan, where hundreds of Taleban and al-Qaeda fighters are believed to be hiding.
It came under rocket attack late on Tuesday.
Shortly afterwards, a group of armed men approached the camp and the Italian troops opened fire on them.
"Security personnel engaged hostile elements, presumably wounding one of them, while the others escaped," Italian military spokesman Lieutenant Gianfranco Oggiano said, the Reuters news agency reports.
No Italians were injured in the incident, Lieutenant Oggiano said.
Some 500 Italian troops are based at the Salerno camp.
It was frequently attacked when it was controlled by US troops.
Shortly afterwards, the Chapman Airfield, six kilometres away, was also attacked by unidentified men.
US military spokeswoman Captain Alayne Cramer said the attackers withdrew after US troops opened fire.
"We don't know if it was the same personnel that moved from Salerno to Chapman," Captain Cramer said.
Up to 8,000 US troops are in Afghanistan leading a coalition of forces hunting remnants of the Taleban and al-Qaeda, which the US blames for the 11 September, 2001 attacks on New York and Washington.