The US threatens investors in Iran

The United States has said it will carefully examine any further plans to build oil and gas pipelines across Iran and would take action against firms investing there.

The announcement, by the State Department, came after the first exports of gas from Turkmenistan to Iran began with the inauguration of a new pipeline between the two countries.

The State Department said the new pipeline was not covered by its laws against investment in Iran, imposed because the US believes Tehran sponsors what it calls international terrorism.

But a State Department spokesman James Foley said Washington would look closely at plans by the Anglo-Dutch company, Shell, to extend the new pipeline across Turkey and into Europe.

From the newsroom of the BBC World Service