Updated

Tunisia's Defense Ministry says four soldiers were killed by a mine in the mountainous northwest of the country near the Algerian border.

Military spokesman Tawfik Rahmouni said the soldiers were pursuing radical Islamist militants on Mount Ouergha in the Kef region when the blast happened on Wednesday.

On Tuesday, another makeshift bomb exploded, wounding four soldiers and two policemen.

Tunisia's forces have been targeting al-Qaida linked fighters farther to the south in the Mount Chaambi area near the Algerian border for the past year and a half.

Military analyst Mokhtar Ben Nasr said the extremists are now moving north under pressure from the government's campaign.

Tunisia has declared war on the radical Ansar al-Shariah movement that has links to al-Qaida and is blamed for the assassination of two politicians.