Relations between Nasser and Qasim grew increasingly bitter on 9 March, after Qasim's forces suppressed a rebellion in Mosul, launched a day earlier by a pro-Nasser Iraqi RCC officer backed by UAR authorities. Nasser had considered dispatching troops to aid his Iraqi sympathizers, but decided against it. He clamped down on <answer>Egyptian communist activity</answer> due to the key backing Iraqi communists provided Qasim. Several influential communists were arrested, including Nasser's old comrade Khaled Mohieddin, who had been allowed to re-enter Egypt in 1956.
What did Nasser suppress as a result?
Egyptian communist activity