Police in Puerto Rico have launched an investigation into the deaths of at least 16 cats and dogs found near a bridge where dozens of animals were thrown to their deaths seven years ago in a case that sparked international outrage.

Animal activists found the bodies of 11 cats and five dogs strewn underneath a bridge in the north coastal town of Vega Alta after getting calls from citizens.

Authorities said Tuesday that it is unclear how the animals died, although they are pursuing it as a suspected abuse case.

The case highlights Puerto Rico's continuing struggle to curb animal cruelty despite recent actions including education campaigns and approval of a 2008 law to prosecute suspected animal abusers.