Iran repelled a large cyber attack on its infrastructure on Sunday, said the head of its Infrastructure Communications Company, a day after a powerful explosion damaged its most important container port and another round of talks with the U.S. over Tehran's disupted nuclear programme.

"One of the most widespread and complex cyber attacks against the country's infrastructure was identified and preventive measures were taken," Behzad Akbari said on Monday, according to semi-official Tasnim news agency, without giving more detail.