It was not immediately clear how many people have been killed, said Ziauddin Mohmoodi, the deputy regional police commander for western Afghanistan. He said earlier reports of a gunbattle between militants and the Italian military were incorrect, explaining that while there was shooting after the explosion, it came from the base.
The area was calm by midday, Mohmoodi said. He added that there had been a second explosion about a mile (two kilometers) from the base but they did not yet know any details on that blast.
A NATO spokesman confirmed there was an attack near the Italian military compound in Herat city. British army Maj. Tim James said they had reports of an explosion and small arms fire but stressed that the reports were still very preliminary.
The base in Herat city houses an Italian provincial reconstruction team, a collection of military and sometimes civilian workers who are tasked with helping build up local government and infrastructure.
Herat city is relatively peaceful compared with Taliban strongholds in the south and the increasingly volatile north. Attacks are rare inside the city, though there are a number of volatile districts on its outskirts.