Authorities are investigating a white powdery substance that was delivered in greeting cards to three locations Monday in the Merrimack Valley, said State Fire Marshal Stephen D. Coan.

“Our regional hazmat team for that area of the state has ­responded to three locations, in Methuen, Lawrence, and ­Haverhill,” said Coan. “Each one of them has some similarity. Each recipient received a greeting card through the US mail today with a return ­address in Haverhill that contained an unidentified white powdery substance.”

The first envelope was delivered to a Home Depot in ­Methuen at 10 a.m., Coan said. Police were notified a short time later that two locations in ­Lawrence and Haverhill had ­also received suspicious cards, he said. The cards did not ­include any threatening message, Coan said.

A preliminary test of the substance found in Methuen ­indicated the powder was not hazardous, but it will be sent to the state Department of Public Health laboratory for further analysis, he said.

The locations in Lawrence and Haverhill were active scenes, and the substances will be tested, Coan said. He did not disclose the exact locations but said that they are not residences. Local police are investigating the incidents, and the FBI has been notified, Coan said.

‘As far as I know, there have been no exposure issues or any personnel that have felt ill effects.’

No injuries were reported.

“As far as I know, there have been no exposure issues or any personnel that have felt ill ­effects,” Coan said.