Police are searching for vandals who left bizarre notes referencing "World War Three" and "the Rapture" in resident letterboxes after they cut NBN cables in Perth's southern suburbs earlier this week.

NBN Co technicians were called to North Fremantle on Wednesday evening after it was found around 200 local residents had found themselves without an internet or home phone connection.

9 News Perth reporter Elizabeth Creasey said it was later discovered a pillar on Herbert Street had been dug up and had its wires cut at some point on Wednesday evening.

Residents also reported receiving bizarre letters in their letterboxes following the incident, believed to be connected with the vandals.

The notes allegedly left by the vandals. Credit:9 News Perth

"See internet "The Rapture" after the Rapture comes World War Three," read one of the notes.

WA Police confirmed they were investigating the incident, and NBN Co technicians said they hoped to have the node up and running early next week.