The Copenhagen Post said Friday that during the past two days four of the homemade bombs were removed from a playground and a park.

Three of the explosive devices had been placed on a playground on the city's northeast side. Another bomb was found in a Norrebro district park, police said.

Investigators said they had no leads on who created the bombs or why the two sites were targeted.

The Post said hydrochloric acid can be particularly dangerous since the compound has corrosive qualities that can deteriorate human tissue and damage an individual's respiratory system.