>> Warning shots fired in the Persian Gulf. A US Navy ship firing a machine gun to ward off Iranian fast attack craft approaching at what the Pentagon calls dangerous speeds. It's the second encounter with Iran's hard line revolutionary guard in the region this week. The USS Nimitz earlier had a brush with four patrol boats near the Straight of Hormuz.
Reuter's Idris Ali said it could be the start of a new normal.>> We're just trying to figure out whether these are rogue Iranian Revolutionary Guard commanders or this is something which is being directed from the top. Obviously, these things happening so close together does raise the question, is this a new trend?
Are these isolated incidents? But if this continues, it could well become a trend.>> Iran's Defence Minister says the boats were just doing the job, protecting the country's waters. Washington and Tehran have no official diplomatic ties, which means there's no mechanism to try and work out problems. The skirmish has come just as things were starting to look a little less tense between the countries.
>> The hope was that once the nuclear deal was signed in January, that there would be sort of this opening of profiliations, that clearly hasn't happened. At the same time there's a lot of concern in Washington and around some other countries and capitals that the role that Iran is playing in Syria to support Bashar al-Assad and the Russians is causing instability in the region.
>> The Pentagons has its ships are trying to avoid more serious situations in the Gulf. Earlier this year, Iran detained ten US sailors who would mistakenly wandered into its territorial waters.