Held senior positions in the Delek (the intelligence service) and was appointed Commander of Haifa and the Northern District. Participated in various activities, including the sabotaging of the southern railway lines (April 2, 1946), where he was caught in the Bat Yam sand- dunes with 30 of his fellow fighters, tried under the name of 'Mendel Belikovsky' (the pseudonym which appeared in his identity card), and sentenced to seven years imprisonment.
Took part, as an inmate, in the Acre jail break and succeeded in escaping from the prison, but was wounded and captured by the British, who returned him to jail. He was then taken to the central jail in Jerusalem, and in February 1948 succeeded in escaping, together with 11 Lehi and Irgun prisoners.
In 1950 he was the cofounder of the Shelah publishing house, wrote and published books about underground activities under the name of Aryeh Melitz.
Published a book (in Hebrew) entitled "One Truth And No Other" (Yediot Aharonot, 1995).