The Houthis, who launched a number of maritime attacks in solidarity with Hamas, have now started emailing private companies threats, Der Spiegel reported on Monday.
Targeting companies which call at Israeli ports and transport their cargo through the Red Sea, the Bab al-Mandab Strait, the Gulf of Aden, the Arabian Sea and the Indian Ocean, the Houthis threatened future attacks.
"The Houthis obviously have well-researched email addresses, as the threats were also sent to individual contacts," said Irina Haesler, who is a member of the Association of German Shipowners (VDR) management.
VDR said they were in communication with security officials over the threats.
Attacking Israel
In addition to attacking global shipping, the terror group has also stepped up their missile attacks on Israel over the past few months.
Yemen's Houthis claimed to have targeted an Israeli military base in Tel Aviv with ballistic and cruise missiles, the Houthi-owned Yemeni news outlet Al-Masirah claimed in October. The Houthis claimed that missiles successfully reached their target, "bypassing the American and Israeli interception systems," in a statement shared by Al-Masirah.
"This operation comes as a victory for the just cause of the Palestinian and Lebanese people and in support of their resistance," the Houthis added.
In June, they claimed responsibility for attacking four ships in Haifa's port.
JERUSALEM POST STAFF contributed to this report.