The naval war also continued, with the United Kingdom maintaining a blockade of France by sea. Non-combatants Russia, Prussia, Denmark, and Sweden joined to protect neutral shipping from British attacks, but were unsuccessful. British Admiral Horatio Nelson attacked the Danish fleet in harbor at the Battle of Copenhagen, destroying much of the fleet of one of France's more steady allies during the period. An armistice prevented him from continuing into the Baltic Sea to attack the Russian fleet at Reval (Tallinn). Meanwhile, off Gibraltar, the outnumbered French squadron under Linois rebuffed a first British attack under Saumarez in the first battle of Algeciras, capturing a line-of-battle ship. In the second battle of Algeciras, four days later, the British captured a French ship and sank two Spanish, killing around 2000 mostly Spanish seamen for the loss of 12 British.