Soon after, he joined the Fighting Force and took part in numerous operations, such as: the blowing-up of the British Intelligence offices in Jaffa, the attack on the military airfield in Lydda etc.
On March 6, 1946, he took part in the attack on the Sarafand army camp, and was injured in the exchange of fire, together with his friend, Yosef Simchon. They were loaded into a car, which set out for Tel Aviv in order to take them to hospital, but encountered a British roadblock on the way and were arrested. Two months later Ashbel and Simchon were placed on trial before a military tribunal and sentenced to death (June 13, 1946). However, the kidnapping of British officers by the Irgun forced the British High Commissioner to commute the death sentence to life imripsonment.
Ashbel was wounded by British gunfire during the breakout of Acre jail and died of his injuries several hours later.