President Trump has confirmed Iran is in serious discussions with the US following the steady build-up of American military forces in the Gulf. The US president said he hoped negotiations with Iran would lead to something acceptable, as tensions between the two countries remain high. Iran's top security official Ali Larijani also said a framework for negotiations was progressing.

Trump has threatened to intervene in Iran over its nuclear ambitions and after its deadly crackdown on anti-government protests. Iran has said it would respond immediately and powerfully respond to any aggression by land or sea.

Iran is expected to begin a two-day, live-fire naval exercise on Sunday in the Strait of Hormuz - one of the world's most important shipping routes and a key route for energy supplies. Around a fifth of the world's traded oil passes through the waterway, which is about 33km (21 miles) wide at its narrowest point between Iran and Oman. Iran has in the past threatened to close the waterway in the event of an attack on it.

The US has warned Iran against any unsafe and unprofessional behaviour near its forces in the area. As part of its build-up of forces, the US has sent its aircraft carrier USS Abraham Lincoln to the region and late last week US central command said it was operating in the Arabian Sea.

Iran's Foreign Minister Abbas Araghchi responded by saying: The US military is now attempting to dictate how our Powerful Armed Forces should conduct target practice in their own turf.

On Saturday, two explosions in Iran heightened anxiety in the country. Local authorities said a blast that killed one and hurt 14 at a building in the southern port city of Bandar Abbas was caused by a gas leak. In another explosion in the south-western city of Ahvaz, at least four people were killed, again attributed to a gas leak.

On Thursday, Trump stated he had told Iran that it had to do two things to avoid US military action: Number one, no nuclear. And number two, stop killing protesters.

The US-based Human Rights Activists News Agency has confirmed the killing of more than 6,300 people since the unrest began in late December, with another group warning the final toll could exceed 25,000. Protests have been described as facing the most lethal crackdown ever witnessed. Iran's Supreme Leader accused protesters of attacking police and other facilities, claiming, The coup was suppressed.\