A possible near miss just outside Norwich between a plane jetting off from the city's airport and a military aircraft is being probed by aviation authorities.

A possible near miss just outside Norwich between a plane jetting off from the city's airport and a military aircraft is being probed by aviation authorities.

The Civil Aviation Authority (CAA) confirmed it was investigating reports that the Aberdeen-bound BMI flight and a military aircraft got too close to each other at 11,000 ft last month.

The incident is one of 30 to have been reported to the CAA involving aircraft near Norwich since 2002.

The latest incident happened 10 miles north-west of Norwich at 8.46am on Thursday, April 10, shortly after the E135, which can carry around 40 passengers took off from Norwich International Airport.

An aircraft proximity report, which are logged by pilots or air traffic controllers if they feel the distance between aircraft, as well as their positions and speed, compromised, or might have compromised, the safety of the aircraft involved, has been drawn up into the incident.

It is now being considered by the UK Airprox Board, which investigates near-misses involving aircraft in British airspace, and will determine the level of risk it presented and publish a report on its findings.

Recommendations will be published where appropriate, to learn lessons from what happened and reduce the chances of such an incident happening again.

A spokesman for the Ministry of Defence said no details would be released while the investigation is ongoing, while a spokesman for BMI confirmed the operator had submitted a report but could not comment further.

Nationally during 2006, the last year for which full data is available, there were 74 Airprox incidents involving commercial air transport and 92pc were assessed as having no risk of collision.

A Freedom of Information requested revealed 30 incidents at heights of up to 37,000ft had been reported to the Civil Aviation Authority within 30 miles of Norwich International Airport since 2002.

In more than half of cases investigators established that no risk of collision existed. But in 11 cases they deemed the safety of aircraft was compromised and on three occasions the board said there was an actual risk of a crash.

In October 2002 a Tornado and a Jaguar came within 100ft of each other 23 nautical miles North-northeast of Coltishall.

In July 2003 a Piel CP301 Emeraude light aircraft flying at 3,000ft near Thetford failed to receive a message from air traffic control about an Agusta A109 helicopter at 3,000ft and flew through its wake.

In June 2004 a Cessna 150 came close to seven gliders at 2,500ft, two miles south of Thetford.