Contemporaneous articles from socialist publications:

https://www.marxists.org/archive/cliff/works/1946/04/palestrike.html
https://www.marxists.org/archive/cliff/works/1946/05/strike.html

According to T Cliff, the strike comprised 32,000 workers, or 15% of the whole working class in Palestine at that time - 26,000 Arab Palestinians and 6,000 Jews.

The strike was denounced by the Histadrut and by Zionist Hebrew newspapers, as well as by at least one (presumably bourgeois) Arabic newspaper which denigrated the strike as "Zionist".

Per Jacobin:

The largest postwar Arab-Jewish joint labor action was the April 1946 strike of blue- and white-collar postal, telegraph and telephone, and railway workers throughout the country — the first general strike of railway and postal workers in Palestine. They were soon joined by government civil servants and Public Works Department and port workers, with about twenty-three thousand workers taking part in total.

The incapacitated British Mandate administration had to concede to many of the strikers’ demands, including wage increases, a cost-of-living allowance, and pension improvements. Neither the Histadrut leaders nor conservative Palestinian nationalists welcomed this expression of Jewish-Arab solidarity.

Unfortunately, after the strike succeeded, this binational solidarity did not really continue much further. The Histadrut would go on to undercut other expressions of Jewish-Arab solidarity in order to solidify Jewish nationalism. The following year, the UN would announce its partition plan for Palestine, and historical Palestine would devolve into civil (and then regional) war.

Relevant Haaretz article by Hadash member Odeh Bisharat: https://archive.ph/kEIUb