A paragraph break is appropriate here since the scene changes from Joppa to Jamnia (so Good News Bible).

But learning that the men in Jamnia meant in the same way to wipe out the Jews who were living among them: As in Joppa, Jews were a minority among the people living in Jamnia, and not considered citizens of the city. Judas heard that the citizens of Jamnia intended to kill all the Jews in their city just as in Joppa. The connector But is not correct. A better way to begin this verse is “When Judas heard that the people of Jamnia…” or “When they [or, people] informed Judas that the people of Jamnia….” Jamnia was another seacoast town, about 20 kilometers (12 miles) south of Joppa. Contemporary English Version provides a helpful model for this verse, saying “Judas was then told that the citizens of Jamnia also planned to kill their Jewish neighbors.”

Quoted with permission from Bullard, Roger A. and Hatton, Howard A. A Handbook on 1-2 Maccabees. (UBS Helps for Translators). New York: UBS, 2011. For this and other handbooks for translators see here.