Nicaragua has filed a suit at the U.N.'s highest court seeking to stop Costa Rica from building a road along the banks of the San Juan river that it claims is destroying the environment.
The legal action filed late Thursday at the International Court of Justice is the latest in an ongoing dispute between the two countries over rights to the ecologically sensitive river that forms a common border.
Nicaragua claimed the construction had dumped uprooted vegetation, felled trees and tons of sediment that threatened endangered species, wetlands and the water quality of the river.
The Nicaraguans asked the court to order a return to the previous situation, and for Costa Rica to pay dredging costs to restore the river.
Earlier this week, the Central American Court of Justice also agreed to hear Nicaragua's complaint about Costa Rica's highway construction.
The two Central American countries came close to an armed standoff earlier this year over Costa Rica's complaint against Nicaraguan dredging it said was to improve navigation on the river.
The U.N. court, also known as the World Court, ordered both countries to withdraw armed forces from the area. But it declined to order Nicaragua to cease work, saying it was unclear that it was causing irreparable damage.