From the BBC:
"British Airways said it had cancelled all its short-haul UK and European inbound and outbound flights to and from Heathrow until 1500 BST.

Stringent security measures have been put in place at airports across the UK.

German carrier Lufthansa, Spanish airline Iberia and Olympic have all cancelled flights to the UK.

There are no flights from Brussels to London.

In addition, Air France flights from Paris to Heathrow have been grounded temporarily while the backlog at the airport is cleared."

Anything from BMI? Would you believe web site is "closed for maintenance"1 Well thats what I found when I tried it. BA web site is keeping passengers informed. Do BMI have the same facility?