Istanbul police issued a bomb attack warning for crowded places Monday after the July 20 bombing in Suruç, in southeastern Turkey, that killed 32 people and left hundreds wounded. In an alert sent to all its units, the department warned of possible attacks on public transportation in the city after Turkey began bombing the Islamic State group and Kurdistan's Worker's Party (PKK) in northern Iraq and Syria. 

The memo from Deputy Police Chief Mustafa Çalışkan said there is information that attacks will continue and could target public transportation vehicles, police buildings, security forces and police lodging, according to Today's Zaman. Police units have been asked to review security measures and inform Istanbul's counterterrorism unit of any suspicious situations, reported Hurriyet Daily News.

The warning referenced the Suruç bombing and the beginning of Turkey's campaign bombing ISIS positions starting July 24 as part of an international coalition, according to Today's Zaman. Turkey, which shares long borders with both Syria and Iraq, also opened its airbases to U.S. warplanes as Islamic State militants have pushed on the Turkish border. 

suruc If a spokesperson for the Syrian People’s Protection Units makes good on his threat, the price to pay for Turkey’s increased role in the anti-ISIS coalition could be Kurdish allegiance to the U.S. Pictured: Protesters and mourners gathered at the scene of a suicide bombing that killed at least 31 people in Suruç, Turkey, July 22, 2015. Photo: Zeki Mafzan

Turkey also began bombing PKK militants after more than a year of peace talks with the group's leaders. The PKK, a Kurdish separatist group labeled a terrorist organization by both the United States and the European Union, has also been fighting against ISIS along Turkey's border. Turkish Prime Minister Ahmet Davutoğlu said the attacks were in retaliation for PKK murders of police officers in Ceylanpınar.

Meanwhile, the British Foreign Office advised British tourists in Turkey on Tuesday to avoid traveling on trains and buses after "there were reports of possible threats to public transport in Istanbul," reported the Express. The Foreign Office also recommended against all but essential travel to certain areas of Turkey and suggested that the Istanbul transit stations most at risk were Taksim, Osmanbey, Yenikapi and Haciosman.