Members of Iran’s negotiating team who are in the Austrian capital for a last-ditch efforts to revive the 2015 nuclear deal have attended a Shiite religious mourning ceremony in Vienna.

The twitter account of the Islamic Republic’s embassy in Austria published photos of Tehran’s lead negotiator Ali Bagheri-Kani at the mourning ceremonies of the Islamic month of Muharram. The event was held at Vienna’s Islamic center of Imam Ali, a Shiite mosque. 

The highlight of the month-long ceremonies of Muharram are the Days of Tasu'a and Ashura, the anniversary of the slaying of Shiite Imam Hussein and his 72 companions by his rivals to the leadership of Muslims. Ceremonies have been held for centuries in Iran and among Shiites in other countries, marking the event in the 680 AD battle of Karbala, in present-day Iraq, and have gained greater state support since the 1979 Islamic Revolution.

This round of the Vienna talks reportedly focus on a text circulated in late July by Josep Borrell, the European Union foreign policy chief, to bridge gaps between the United States and Iran over how the Joint Comprehensive Plan of Action -- or JCPOA -- can be revived. It is unclear how specific are proposals in Borrell’s text and how far he outlines a process.

European officials have presented a tough face to reporters gathered outside the Palais Coburg hotel in Vienna, insisting that the current talks will not be “reopening” negotiations, and urging Tehran not to make “unrealistic demands.”