South Korean intelligence is said to have found signs that its northern neighbour may be preparing a second nuclear test. It is unclear how reliable the indications are, however.

Some U.S. television networks have reported satellites noting suspicious activity near the site of the first charge’s detonation. Secretary of State Condoleezza Rice warned Tehran it could face similar sanctions as North Korea for pushing ahead with its own nuclear programme. The international community had shown itself ready to respond to threats of nuclear proliferation, Rice warned, adding that the United Nations Security Council would start work on a sanctions resolution against Iran this week.