At least 518 migrants from sub-Saharan Africa have been taken back to Morocco since August 8, including the latest group, according to an AFP tally based on Moroccan military sources.
The navy found the latest group, of 190 migrants, in "waters between Tan-Tan and Dakhla", a military source told state news agency Map. Among them were 11 women, Map said.
Spain's Canary Islands are only about 150km off southern Morocco, west of Tan-Tan.
The Canary migratory route has experienced a marked surge in activity in recent weeks.
100,000 migrants cross the Channel in five years - in pictures
Moroccan authorities said they stopped 26,000 irregular migration attempts in the first five months of 2023.
In the first six months, 7,213 migrants reached the Canary Islands by boat, Spanish Interior Ministry figures show.
At least 13 Senegalese died in mid-July when their boat sank off Morocco, authorities in Senegal say.