First and second types of vector load instruction are provided. For the first type, a response action is performed when an exceptional condition is detected for a load operation performed for a first active data element of at least one vector register, but when the exceptional condition is detected for an active data element other than the first active data element, the response action is suppressed and element identifying information is stored identifying the element which caused the exceptional condition. For the second type, the response action is suppressed and the element identifying information is stored when the exceptional condition arises for any active data element. This approach is useful for allowing loop speculation and loop unrolling to be used together to improve performance of vectorised code.