One police officer and three militants were killed in clashes between Turkish security forces and Kurdish insurgents in southeast Turkey's largest city of Diyarbakir on Tuesday, security sources said, as local authorities declared a curfew.
The renewed surge in fighting came after 37 people were killed in an Ankara car bombing that security officials said involved two fighters - one female - from the Kurdistan Workers Party (PKK).
Following that bombing, the Turkish military launched air strikes on Monday and struck northern Iraq's Qandil mountain area where the PKK's main bases are, and the military said 45 PKK insurgents were believed to have been killed.
The strikes by F-16 and F-4 jets destroyed two weapons depots and two Katyusha rocket positions, the military also said in its statement on Tuesday.
One police officer and three militants were killed in the fighting in Diyarbakir's Baglar district, the security sources said. A curfew was imposed in Baglar's Kaynartepe neighbourhood from 3 a.m. (0100 GMT) in the face of moves by PKK militants to set up barricades, dig ditches and plant explosives in the area, local authorities said.
PKK fighters blocked roads and halted vehicles in the area and clashed with security forces sporadically through the night as a police helicopter flew overhead, witnesses said.
Violence has surged in the mainly Kurdish southeast since a 2-1/2 year ceasefire with the PKK collapsed in July. The militants have focused their strikes on security forces in southeastern towns, some of which have been under curfew.
A curfew was also declared on Monday in the southeastern town of Sirnak, alongside ones declared in Yuksekova, near the Iranian border and Nusaybin, near the Syrian border.