More than 100 people were arrested and four police officers were injured early Thursday when protesters clashed with Boston police as a pro-Palestinian encampment at Emerson College was cleared. The encampment in Boylston Place Alley is one of several set up by students at Massachusetts colleges to show solidarity with the pro-Palestinian protesters who were arrested at Columbia University in New York earlier this week.An Emerson student said an announcement was made at 1 a.m. in the encampment, which is off Boylston Street, saying anyone in the alley would be arrested. Boston police officers walked out of the Massachusetts Transportation Building at 2 a.m. and made their way through the crowd in the alley.Video from the scene showed dozens of officers in the area, many of whom were wearing protective gear.”I saw one student get shoved to pavement and hands behind them. Protesters seemed compliant — not fighting back or …