Christian-led army troops battled Moslem militiamen along Beirut's demarcation line Tuesday, sending dozens of shells crashing on residential areas and killing at least 20 people, including children on their way to school.

Police said the fighting, the worst in the city in two years, erupted late Monday when the pro-Syrian militiamen shelled two Christian-run ports in east Beirut, prompting the army to bombard several areas in Moslem west Beirut.At least 20 people were killed and 75 others wounded in the clashes.