Houses across the city have been set on fire following a knife attack earlier this week.
The US president warns Iran "will have to pay the price" for taking too long to agree a deal, after Tehran vows retaliation to any attacks.
The Microsoft co-founder has repeatedly denied any wrongdoing or knowledge of his former associate's illegal activity.
A night of disorder in Belfast saw people forced to flee their homes, in protests that followed a knife attack in the north of the city.
"This is similar to a doctor that is licensed to practice family medicine but is doing brain surgery in their office," police said.
Cars and a bus were set on fire and families were driven from their homes as the stabbing attack caused tensions to spill onto the streets.