LA PAZ, March 10 (Xinhua) -- Bolivia on Saturday unfurled an almost 200-km-long "maritime flag" to highlight its demand for access to the Pacific Ocean lost to neighboring Chile in a 19th century war.

Tens of thousands of people took part in the symbolic gesture, helping hold up the long blue banner along the highway linking the capital La Paz with Oruro.

"Today is a historic event ... we have registered from Apacheta to Casco del Minero a 196.5-km flag of maritime revindication, a world record," Bolivian President Evo Morales said.

The ceremony is aimed to boost Bolivia's case in the lead up to a key hearing of its demands starting March 19 at the International Court of Justice at The Hague.

Bolivia intends to recover access to the Pacific Ocean which it lost to Chile in the 1879-1883 war.