Turkish jets bombed targets of the Kurdistan Workers’ Party (PKK) in southeast Turkey, officials said Tuesday, the first strikes on the outlawed group since a 2013 ceasefire amid growing concern about the peace process.

Turkish F-16 jets dropped bombs late Monday on PKK targets in the village of Daglica in the Kurdish-majority Hakkari province near the border with Iraq, a security source told AFP on condition of anonymity. In a separate incident also Monday, Turkish attack helicopters struck at PKK targets around the village of Geyiksuyu in the Tunceli province of eastern Turkey following raids by the PKK.

The fierce clashes between Islamic State (IS) insurgents and Kurdish forces in the key Syrian town of Kobane have shaken Turkey’s fragile peace process with the PKK, blacklisted as a terrorist organisation by Ankara and much of the international community.

Frustrated with Turkey’s lack of action to stop the IS advance in northern Syria on fellow Kurds, Turkey’s Kurdish community has taken to the streets in several cities in the southeast over the past week, with scores killed in deadly clashes.President Recep Tayyip Erdogan blamed the unrest on the “dark forces” seeking to sabotage the delicate peace process with the PKK to end 30 years of violence that has claimed at least 40,000 lives.

 The air strikes came one day before the October 15 deadline given by the PKK’s overall leader Abdullah Ocalan, who is serving a life sentence in an island prison on the sea of Marmara, for a roadmap to salvage the flagging peace process.

But Nihat Ali Ozcan, security analyst at Ankara-based TEPAV think tank, said while the peace process could well be “dead in the water” one day, it would not be over just because of these latest incidents. “It is not an easy task to manage the peace process,” he said. Turkey, a NATO member, has tightened security on its volatile border after the escalating fighting in Kobane sparked the exodus of 200,000 refugees.

Prime Minister Ahmet Davutoglu, in a speech to his ruling party lawmakers Tuesday, made no mention of the air strikes but said the government was still committed to making peace with the Kurds. “The peace process is not linked to Kobane. It’s not linked to any development that takes place outside our borders,” Davutoglu said.

Meanwhile, military commanders from more than 20 countries met Tuesday in Washington to discuss the fight against militants in Syria and Iraq after more than two months of US-led air strikes failed to halt the militants’ advance.

The US military’s top-ranking officer, General Martin Dempsey, hosted the talks at Andrews Air Force base outside the US capital, the first such gathering of top brass from so many nations since the coalition against the Islamic State group was formed in September.

“This meeting provides an opportunity to take stock of coalition progress to date and continue to align and fully integrate the unique capabilities of coalition partners,” said Alistair Baskey, spokesman for the US National Security Council.

President Barack Obama was due to meet the coalition commanders later on Tuesday and looked forward to discussing “additional measures that the coalition can take to degrade and ultimately destroy” the IS group, Baskey said.

US officials said no dramatic announcements were expected to emerge from the talks but promised that the meeting would ensure better coordination among the coalition members.

“This is just to make sure everybody is working off the same song sheet,” a US defense official, who spoke on condition of anonymity, told AFP.

Despite daily bombing raids by coalition aircraft, the IS group has captured nearly half of the Syrian border town of Kobane and seized most of Iraq’s largest province, Anbar.

The American officer overseeing the air campaign in Iraq and Syria, General Lloyd Austin, head of Central Command, was expected to brief the military chiefs and provide an update to Obama.

The four-star general has kept a low public profile since air strikes began on August 8 in Iraq and has yet to hold a press conference or answer questions from reporters on the operation.

The meeting will be attended by officers from 22 countries, including all five of the Arab states that are taking part in the air campaign in Syria.

Australia, Bahrain, Belgium, Britain, Canada, Denmark, Egypt, France, Germany, Iraq, Italy, Jordan, Kuwait, Lebanon, the Netherlands, New Zealand, Qatar, Saudi Arabia, Spain, Turkey, the United Arab Emirates and the United States will be represented.

Meanwhile, British police on Tuesday said they had arrested six people on terrorism charges in an investigation linked to the conflict in Syria, where hundreds of British militants are fighting.

The three men and three women were detained in Farnborough and Portsmouth in Hampshire, southern England, and in Greenwich in southeast London.

“Officers would like to reassure residents that the police activity today is in relation to conflicts overseas and is not linked to any immediate threat to local communities,” a spokesman for Thames Valley police said. He explained the reference was to the Syrian conflict.

Two of the men, aged 23 and 26, and two of the women, aged 23 and 29, were arrested on suspicion of “commission, preparation and instigation of acts of terrorism”, police said.

A 57-year-old man and a 48-year-old woman from the city of Portsmouth were also detained on suspicion of “failing to disclose information about acts of terrorism”.

Britain’s Press Association reported that the house in Portsmouth had already been raided by the police in April and is believed to be the family home of Ifthekar Jaman, a British Muslim killed fighting government troops in Syria in 2013.