Pedestrian crossing signs are usually a square standing on one corner or you may call it a fat diamond shape, but some are triangles with the point at the top and the long side a the bottom -- like an upside down Yield sign.
Diamond in the US, Circle in the UK.
triangle
It could be a plus (+) sign
You should warn them and report them to the police right away
It is red and white shaped like a cross.
You will stop and give the pedestrain the right-of-way.
no
no, its a warning sign
A warning sign
Warning sign.
regulatory
warning