ANKARA (Reuters) - Turkish fighter jets and ground forces hit Islamic State militants in Syria and Kurdistan Workers Party (PKK) camps in Iraq on Saturday, in a campaign Ankara said would help create a "safe zone" across swathes of northern Syria.
The strikes followed Turkey's first-ever air attacks on Islamic State in Syria a day earlier and Prime Minister Ahmet Davutoglu told a news conference the heightened security operations will go on.
"These operations are not 'one-point operations' and will continue as long as there is a threat against Turkey," he said.
Turkey has dramatically cranked up its role in the U.S.-led coalition against Islamic State, which has seized much of Syria's north and east, since a suspected IS suicide bomber killed 32 people this week in a town close to the Syrian border.
It has also pledged to target Kurdish militants, raising concern about the future of the shaky Kurdish peace process. Critics including opposition politicians accuse President Tayyip Erdogan of trying to use the campaign against Islamic State as an excuse to crack down on Kurds.
Turkey was long a reluctant member of the coalition against Islamic State, a stance that annoyed NATO ally Washington, and this weekend's move into the front line appears to be a response to the suicide bombing in the border town of Suruc.
Many of those killed in the Suruc attack were Kurds and it sparked violence in the largely Kurdish southeast by militants who say Erdogan and his Islamist-rooted AK Party have covertly supported Islamic State against Syrian Kurds.
Ankara denies the accusation.
On Friday, as its planes bombed Islamic State in Syria for the first time, police rounded up hundreds of suspected Islamist and Kurdish militants in cities and towns across Turkey, with nearly 600 people having been detained as of Saturday.
"It is unacceptable that Erdogan and the AKP government have made a fight against the Kurdish people part of their struggle against Islamic State," the pro-Kurdish Peoples' Democratic Party (HDP) said in a statement.
It is not known whether the deal struck with Washington this week allowing coalition forces to use Turkish bases for bombing raids against Islamic State will entail the creation of a "safe zone" in northern Syria, something Turkey has long sought.
But Foreign Minister Mevlut Cavusoglu told a news conference that "safe zones will be formed naturally" as swathes of northern Syria are cleared of Islamic State militants.
"We have always defended safe zones and no-fly zones in Syria. People who have been displaced can be placed in those safe zones," he said.
Washington says direct military pressure on Islamic State, not a safe or no-fly zone, is the best way to end the region's fighting and refugee crisis.
The deal to use Turkish airbases will greatly shorten distances to targets and potentially make the aerial campaign President Barack Obama says is intended to "degrade and destroy" Islamic State capabilities more effective.
Saturday's air strikes hit Islamic State positions in Syria and PKK locations in northern Iraq, including warehouses and living quarters, Davutoglu's office said in a statement.
Simultaneously, Turkish land forces fired on Islamic State and the PKK, it said.
The attacks on the outlawed PKK, which has waged a three-decade insurgency against Turkey, could kill off stumbling peace talks between the group and Ankara, which were started in 2012 but have been stalled lately.
"The truce has no meaning anymore after these intense air strikes by the occupant Turkish army," the PKK said in a statement. One militant was killed and three wounded, it said.
Erdogan took a hefty political risk in starting peace talks in 2012 with the Kurds, who represent nearly 20 percent of Turkey's population. They now accuse him of backtracking on promises.
The military actions drew protests in Turkey, where police in the capital Ankara fired tear gas and water cannon to break up a demonstration of around 1,000 people, and in France, where around 1,500 people marched in support of the Kurds.
"Turkey is playing a double game. It is trying to convince international media that it's hitting Daesh but the reality is that it's bombing Kurds over there in northern Iraq," one of the protesters, Kurdish doctor Saleh Mustapha, said, using another name for Islamic State.
Istanbul authorities said they would not let organizers go ahead with plans for a peace march planned for Sunday, citing concerns about security and dense traffic.
Local media reported attacks on police officers in a Kurdish neighborhood of Istanbul. Such violence has become more common, with other officers killed this week. PKK militants have accused police of working with Islamic State.
Addditional reporting by Gulsen Solaker and Orhan Coskun and Mert Ozkan in Ankara and Pauline Ades-Mevel in Paris; Writing by David Dolan; Editing by Mark Heinrich and Catherine Evans