[HDB Common Corridor] Can window grilles really prevent break-ins / burglaries?

[MikeyBoy 0]

I live in HDB with common corridor. Always been paranoid about burglaries and break-ins. What is the best way to secure common corridor?

 

I see those window grilles and I think if the burglar can get past the window, he can probably open the window grilles from the outside unless you put a padlock on it.