More details have emerged about the life and possible Islamic State affiliations of Diana Ramazova, the Russian citizen identified by Turkish media as the suicide bomber who attacked a police station in Istanbul’s historic Sultanahmet quarter last week, killing one officer and wounding another.

According to the daily newspaper Hürriyet, 18-year-old Ramazova changed her life after meeting Abu Aluevitsj Edelbijev, a Norwegian citizen of Chechen origin, on an online forum. The paper says she started wearing an Islamic veil and led a religiously conservative lifestyle. The couple allegedly met in Turkey, and were later married by a religious official in Turkey or Syria.

Turkish border police records show that Ramazova entered Turkey in May 2014 as a tourist, whereas there is no trace of her husband crossing the Turkish border, fuelling suspicion that he entered irregularly. Hürriyet reports that the couple then spent three months “on honeymoon” in Istanbul. Police have been sifting through Ramazova’s and Edelbijev’s photographs taken in Turkey and Syria, trying to establish their movements and whether the couple were in contact with a third person while residing in Istanbul.

Norwegian and Turkish security sources claim the couple left Turkey for Syria last July, where they joined the ranks of Isis, taking on the noms de guerre Idris and Sumeyra. In October, Norwegian anti-terror police opened an investigation against Edelbijev and one of his friends suspected of being members of Isis, and his accounts in the country were subsequently frozen.

In December, Edelbijev was allegedly killed fighting for Isis. On 26 December, widowed Ramazova illegally crossed the Syrian border back into Turkey, where she went first to Gaziantep and later to Istanbul, reportedly by taxi. It remains unclear whether she established contact with other Isis militants inside Turkey, or where she found the money for the taxi ride almost 1,250 miles across the country and where she allegedly procured the two hand grenades used for the attack on the Sultanahmet police station.

She stayed in an Istanbul hotel until 6 January, where she made contact with a woman of Russian origin. Ramazova, who was two months pregnant, died during the attempt to detonate the grenades in front of the Istanbul tourism police station, killing one police officer and wounding another.

Speaking to the press this week, the Turkish foreign minister, Mevlüt Cavusoglu, expressed concern about Isis fighters returning to Turkey from Syria and Iraq.

“A common concern about the foreign fighters is: what will happen when they return to their countries? We also have this concern,” he said.