Amid continued sabre-rattling from Tehran and the west over an EU oil embargo and the free movement of oil ships through the Straits of Hormuz, Channel 4 News looks at the increasing tension.

An Iranian nuclear scientist has been killed by a bomb placed on his car by a motorcyclist in Tehran, the fourth such attack on nuclear experts in the country in two years. Lindsey Hilsum reports.

Defence analyst Anthony Tucker-Jones assesses where conflicts are most likely to erupt over the next 12 months.

Tehran says it has successfully test-fired two long-range missiles during military exercises in the Gulf, amid rising tensions between the west and Iran over its nuclear programme.

As Iranian diplomats leave the UK on the orders of William Hague, Channel 4 News hears that the move is a blow to "ordinary" Iranians.

An American woman who spent 14 months in an Iranian prison accused of spying has spoken to Channel 4 News about the plight of two men who are still being held in Tehran.

Iran's spy chiefs say they have foiled an American plot to recruit agents in the Islamic Republic.