Petar Sokolov

[2] In 1899, together with Slavi Merdjanov, Pavel Shatev and Petar Mandjukov, they dug a tunnel under the central office of the Ottoman Bank in Istanbul, where they planned to set a dynamite.

Soon, however, an Armenian revolutionary was trying to supply to the Bulgarians in the Ottoman capital explosives, but the Turkish authorities managed to arrest him.

[3] Merdzjanov and Sokolov went to Sofia and began to think up new ideas, one of which was to hold up the Orient Express on Turkish territory near Adrianople, and to gain possession of the mail in order to finance future actions.

In pursuit of this plan, they went to the Adrianople area in July 1901, with a cheta consisting of ten men, equipped with the help of Pavel Genadiev, the Supreme Macedonian Committee's representative in Plovdiv.

The cheta managed to place a large quantity of dynamite on the railway line, but something went wrong, and the train passed undamaged.