The soldier died on Saturday evening in the province of Lahej in an area called Jad'aa, according to a local government official. He said the ambush was carried out by armed men.

On Saturday secessionists set the government a 48-hour deadline to release southern leaders or else it "would not be responsible" for the lives of two kidnapped soldiers, the opposition Aden News Agency reported.

The soldiers had been on leave in their hometown of Taizz and were returning to their barracks when they were seized in Lahej the same day, the defense ministry said.

Yemen's south is home to a number of secessionist factions complaining of political and economic marginalization, most of which call for a peaceful resolution to their standoff with Sanaa.

In February, Sanaa concluded a truce deal with northern Shiite rebels, who complain of discrimination by the government, bringing an end to the latest round of fighting in a conflict that has been waged since 2004.

Yemen, located by a major shipping lane, is also facing Al-Qaeda militancy.