Anti-terrorist police found potentially lethal poison ricin at an address in north London. Six Algerian men are being questioned in connection with the discovery, made following an intelligence tip-off. The men were arrested on Sunday morning and are in their late teens, 20s and 30s. Tony Blair said the arrests showed the continued threat of international terrorism was "present and real and with us now and its potential is huge". The intelligence services are said to be "shocked and worried" by the discovery and are looking at possible links with suspected Islamic extremists.