Town officials say a substance found on several mailboxes on Sullivan's Island was found not to be hazardous. 

Town administrator Andy Benke said the investigation started around 1:30 p.m. when a resident reported finding a substance in his mailbox. 

A total of 14 mailboxes had the substance on them, officials said. 

Authorities say they are not sure what the substance is, but it was found not to be hazardous and not a threat to the community. 

The investigation is continuing. 

Responding units included members of the Charleston and Mount Pleasant Hazmat teams, a bomb squad, FBI agents, and fire and medic officials.

Earlier in the afternoon, Mayor Pat O'Neil said tests were being run on the substance and no dangerous material had turned up, but said those tests are continuing.

Charleston County dispatchers say the incident was reported at Station 27.

The call came in at noon.

Town officials had earlier urged people not to approach or open curbside mailboxes until further notice.

Anyone who has previously noticed a white powder substance in their mailbox should contact Charleston County Consolidated Dispatch at 843-743-7200 immediately.

Officials say residents were being alerted via automated call alerts, Nixle and the town's website.

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