Tallinn -- One of the largest searches for unexploded sea mines dating from the World War Two began Monday off Estonia, some 70 years after the start of the conflict on September 1, 1939.

"The joint military operation called Open Spirit that started Monday and will last until September 11, 2009 is attended by 16 military ships from France, Denmark, Sweden, Poland, Germany, Lithuania and Estonia," Ingrid Muhling, spokeswoman for Estonia's military, told AFP.

"In addition, a special joint unit with military divers from the US, Germany and Estonia is screening the sea bed for mines in the operation," she said.

Minesweeping operations in Estonian waters have been organised since 1994 with nearly 600 mines being found, while the estimated number of all unexploded mines in the Baltic Sea is around 80,000, most dating from WWII, Muhling added.

Military divers are to search for mines in two locations -- around Naissaare island located in Tallinn bay, some ten kilometres (six miles) from the capital, and near Hiiumaa island, in north-west Estonia, Muhling said.

During the post-war Soviet era Naissaare island was closed to the public, being used as a military base storing more than 6,000 sea mines that have since been removed.

Monday also marked 15 years since the last Soviet troops withdrew from Estonia after the ex-Soviet Republic regained its independence in 1991. Estonia, which joined the European Union and NATO in 2004, has three Sandown Class minehunters and a special unit of divers to search for and retrieve mines.

AFP/Expatica