Police in south-east England has launched an investigation after a small explosive device was sent to an office of Prime Minister Tony Blair's governing Labour Party.
A police spokeswoman said the contraption was found in a package delivered to the office in Cambridge on Wednesday after a member of staff raised the alarm.
No one was hurt.
"We analysed the package and discovered that it did contain a small explosive device," the police spokeswoman said.
"Had it gone off, someone would have been hurt," she added.
Police are expected to give more details about the incident at a press briefing in Cambridge on Thursday.