Three Turkish soldiers killed in Kurdish mortar attack from Iraq

"Three of our brothers in arms died as martyrs after mortar fire from northern Iraq by terrorists," the ministry said, in reference to the Kurdistan Workers Party (PKK) group.

A fourth soldier was wounded, it said in a statement.

The attack targeted a military base in the border province of Hakkari, the ministry said, adding that the Turkish army had responded with aerial bombardments and artillery fire.

The defence ministry also said that another Turkish soldier had been killed on Saturday in northern Syria by the People's Protection Units (YPG), a Kurdish militia closely allied with the PKK, but which has the backing of Western powers in its fight against the so-called Islamic State (IS).

The PKK has waged an insurgency against the Turkish state since 1984. The conflict has claimed more than 40,000 lives.

The militant group's deployment in northern Iraq has been a constant source of tension between Baghdad and Ankara, with Turkey pressing Iraq to play a bigger role in fighting the group.

The PKK is branded a terrorist group by Turkey, the United States and the European Union.

The group's prominent jailed leader Abdullah Ocalan has not been allowed to see his lawyers since 2011.

Ocalan has in the past conveyed messages to his rebel group through his lawyers.

Nearly 3,000 people in 90 prisons across Turkey are refusing food in protest of his jail conditions, rights groups say.

Hundreds of Kurdish inmates ended a similar hunger strike in 2012, heeding a call by Ocalan.

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