Authorities in the Cape Verde islands are waiting for experts from Spain to help determine why more than 100 dolphins died on a local beach.
Local media reported that around 200 melon-headed dolphins were found on a beach on Boa Vista island on Tuesday.
Officials, residents and tourists on the island off west Africa managed to drag some of them back out to sea, but many returned.
Bulldozers buried 136 dead dolphins.
The group said vets from the University of Las Palmas in the Canary Islands are due in the coming days to perform tests.