Costa Rica's National Emergencies Commission (CNE) announced a red alert on Sunday after the spill of 180 tonnes of ammonium nitrate into the waters of the central Pacific coastline of the Central American country.

The government body declared that the chemical spill, used as agricultural fertilizer, came about after a barge capsized on Saturday afternoon off the coast of the seaside city of Puntarenas, which is 60 kilometers west of the country's capital of San Jose. The boat capsized due to strong waves in the area.

According to the Costa Rican daily "La Nacion", the two crew members aboard the vessel were rescued by emergency personnel.

CNE said that the alert was raised as a precautionary measure to ban all sea-related labor activities such as fishing. People are now banned from going to the sea between the port towns of Caldera and Puntarenas.

The red alert also imposes the same bans on the opposite coast between Pajaros and Tombor beaches in the Gulf of Nicoya.

The CNE continued that Costa Rican health authorities are already carrying out an investigation into the full extent of the impact from the chemical spill.

"As a precautionary measure and to respond to the situations that may arise if the population come into contact with contaminated water and eat contaminated fish, we have been recommended to take direct action to minimize the impact," said a spokesperson from the government body.

The CNE added that they would hold a news conference Sunday afternoon to further report on the spill and its implications for Costa Rica.