4 Russian cruise missiles crash in Iran en route to Syria: US

Four Russian cruise missiles aimed at targets in Syria instead crashed in Iran, a US official said on Thursday, declining to comment on whether there were any casualties.

The official, who spoke on condition of anonymity, said the missiles landed in Iran on Wednesday, but did not provide details about where they might have landed or whether they caused any damage.

Nor would the official say exactly what type of cruise missiles went down, except to say that they were among a salvo fired on Wednesday from Russian warships in the Caspian Sea.

Based on intelligence reports of damage assessments, the US believes that some buildings in Iran and civilians may have been hurt, CNN reported, citing two unnamed US officials.

The Russian Defense Ministry posted a graphic on its website showing 26 missiles overflying Iran and Iraq before striking inside Syria, writing on its Facebook page that the missiles hit their target.

"No matter how unpleasant and unexpected it is for our colleagues in the Pentagon and Langley, our strike yesterday with precision-guided weapons at ISIS infrastructure in Syria hit its targets," the ministry wrote on its Facebook page, using an alternative acronym for the Islamic State (IS) group.

Russia's Defence Ministry denied the anonymous US claims that four of its Syria-bound cruise missiles fired from the Caspian Sea had crashed in Iran.

"Any professional knows that during these operations we always fix the target before and after impact. All our cruise missiles hit their target," ministry spokesman General Igor Konashenkov said in a statement.

The Iranian Defence Ministry has also denied the claims, telling the country's FARS news agency that the US allegations were part of a "psychological war".

Russia has been conducting airstrikes in Syria in defence of the embattled government of President Bashar al-Assad since 30 September.

The missile launches were in support of a major ground offensive by the Syrian army on several fronts in the war-torn country's west.

US Defense Secretary Ashton Carter on Thursday deplored the fact that Russian warships fired the cruise missiles "without warning".