Five people, including two children and a soldier, were killed in clashes between Kurdish militants and security forces in Turkey's restive Kurdish-majority southeast on Thursday, local officials and the army said.

Fighting erupted in the Cizre district of Sirnak province when Kurdistan Workers' Party (PKK) rebels attacked a military outpost with rocket launchers, a security source told AFP.

Four Kurds, including two boys aged seven and 10, died of gunshot wounds in hospital, the source said, adding that six others, including three Turkish soldiers, were also wounded in the fighting.

In a separate incident on Thursday, a Turkish soldier was killed and four others wounded when PKK militants attacked security forces guarding a highway between the Lice district of Diyarbakir and Bingol province in southeast Turkey, the army said in a statement.

Heavy fighting was also raging between the army and PKK militants in the Yuksekova district of Hakkari province, where authorities imposed a curfew late Wednesday.

Pro-Kurdish media reported that several civilians had been killed, but the reports could not be independently verified.

The PKK has been staging daily attacks against Turkish armed forces as the military keeps up air raids and operations against its strongholds in southeast Turkey as well as northern Iraq.

According to figures published Thursday by the state-run Anatolia news agency before the latest incidents, 918 PKK militants have been killed in the latest campaign.

The PKK took up arms against the Turkish state in 1984 in an insurgency to seek independence for the Kurdish-dominated southeast, although its demands later moderated to autonomy and greater rights.

Tens of thousands of people have lost their lives in the conflict and the latest strife has left in tatters a 2013 ceasefire declared by the PKK's jailed leader, Abdullah Ocalan.