US President Barack Obama has ordered sanctions and visa bans for companies and individuals providing technological know-how, computers or other equipment to help Iran and Syria oppress their people.

Obama said in an executive order that the two nations had committed serious human rights abuses through network disruption and by using tracking technology and by perpetrating the "malign use of technology."

The move blocks the property and interests of people that have participated in such trade and suspends their right of entry into the United States. It targets those who have sold, leased or otherwise provided goods, services or technology to Iran or Syria likely to be used to help disrupt, monitor or track individuals through computer of Internet networks. [AFP]