Odd chimney breast bricks

[Paulcarine]

Hi all, opened out fireplace today hoping to find nice brickwork and a builders opening + lintel. But i've got these odd clay/pot like air bricks all the way up. I'm assuming I'm ok to just put a lower lintel in where I want and cut there bricks down where needed?

 

[stuart45]

They look like Terracotta blocks, normally used for partition walls.

 

[Paulcarine]

Thanks for that, at least i've now identified what they are exactly. I'm assuming they can be treated just the same a bricks ?

 

[stuart45]

Cut them with an angle grinder, chisel smashes them.