1.   The point of this is that the firebox opening and the vents must be completely sealed to stop that downdraft.

2.   Haider said the borders of southern Sindh province have been sealed to stop the weapons coming in mostly from northwest Pakistan, which borders Afghanistan.

3.   The frontier with Thailand has been sealed to stop his escape.

4.   Two former high-ranking Taliban officials told The Associated Press last week that the Afghan-Pakistan border cannot be sealed to stop the movement of militants.

5.   Barriers were placed outside schools to prevent car bombs, and litter bins were sealed to stop bombs being planted inside.