At the first sign of a serious attack you are to take off!
It was the most serious terrorist attack inside Israel since 1989.
That battle was the last serious attack on the colony.
The military people took it as a serious attack on their communications lines.
It was the first serious attack for the country in the last five years.
There can be no question of a serious attack to Paris.
At the same time, he simply couldn't believe this was a serious attack on the palace.
A company was not enough guys to hold this place against any sort of serious attack.
On the other hand this may only be a serious attack before the final one which will carry her off.
In order to do this he needed to commit his entire army to a serious attack.