DIYARBAKIR, Turkey (Reuters) - Turkey imposed round-the-clock curfews on 16 villages in its mainly Kurdish southeast on Thursday as security forces tried to root out militants nearby and sacked two co-mayors it accused of supporting the fighters.

A Turkish flag hangs on the historical city walls at one of the entrance of Sur district in Diyarbakir, Turkey July 11, 2016. REUTERS/Sertac Kayar

Authorities in the province of Diyarbakir imposed the lockdown as security forces searched for members of the outlawed Kurdistan Workers Party (PKK) in the hills and woods near the town of Silvan, the provincial governor said in a statement.

Security forces have been battling the PKK since a ceasefire collapsed last year, destroying a two-year peace process that was meant to end a three-decade conflict.

The government says thousands of militants and about 500 soldiers and police officers have been killed since the ceasefire broke down. Human rights groups say about 400 civilians have also been killed.

People will not be allowed to enter or leave the area near Silvan during the curfew, the governor’s statement said.

“It is important for citizens to follow the ban for the security of their lives and property,” it said.

New York-based Human Rights Watch this week accused the government of preventing independent investigations into alleged rights abuses during the lockdowns that include unlawful killings of civilians, displacement of civilians and destruction of private property.

Separately, the Interior Ministry ordered the co-mayors of the town of Mazidagi in Mardin province be removed from office, security sources said.

A prosecutor is investigating the elected officials’ potential culpability after a municipal vehicle was allegedly used in a car-bomb attack on a gendarmes outpost that killed two soldiers and wounded another 12 on July 9.

In the past year, authorities jailed 22 mayors and sacked another 31 for their alleged support for the PKK in the southeast. All are members of a regional party, the Democratic Regions Party (DBP), which denies collaborating with the PKK.

Separately, the district governor in the town of Nusaybin said its four-month curfew would be lifted on July 19. Clashes with the PKK there ended on June 3, but authorities have barred residents from returning as they continued weapons searches and conducted cleanup operations.

It said in a statement 495 PKK militants were killed in the clashes. Officials previously said 70 police and soldiers were killed in Nusaybin, which sits on the Syrian border.