Some 20,000 Israeli followers of the Hasidic mystic Rabbi Nachman of Breslav are expected to make the annual pre-Rosh Hashana pilgrimage to the Ukrainian village of Uman to visit his burial site next week.

According to a report in Yedioth Ahronoth, 130 flights will depart Ben Gurion International Airport for Ukraine between September 11-16.

Amid increasing concerns of terror threats to Israelis traveling abroad, Public Security Minister Yitzhak Aharonovitch on Thursday instructed Israeli police to double the number of officers traveling with the pilgrims this year.

On July 18, a suicide attack killed six people, including five Israeli tourists, in the Bulgarian resort town of Burgas.

The yearly pilgrimage to Uman has crossed sectarian lines to become one of the central events on the Jewish spiritual calendar in Israel. Rabbi Nachman of Breslav died in 1810 at the age of 38, but is remembered fondly by thousands of his followers in Israel.

Aharonovitch’s decision to increase security for this year’s pilgrimage was the result of a recommendation by the Counter-Terrorism Bureau.

Last year’s pilgrimage was marred by a protest in Uman by the far-right nationalist Svoboda Party. The protesters, shouting slogans such as “Ukraine for Ukrainians,” claimed that the influx of Israeli visitors every year to the burial site presented a security and health risk. They also complained about disrespectful treatment of local residents by the pilgrims.