Washington, DC — A dozen groups, including Al-Awda, Jewish Voices for Peace and Answer Coalition, protested the annual conference of the American Israeli Public Affairs Committee (AIPAC). After rallying for Palestinian rights at the White House, large numbers of protesters marched to the conference site, where lines of police officers fended off as many as a thousand people.

As Israel’s occupation of Palestinian territories becomes more repressive, protest against AIPAC–the lobby group which exerts its influence on Congress to obtain economic and military aid for Israel–has been growing. This year, the anticipated presence of several candidates in the presidential election—including controversy magnet Donald Trump—heightened emotions.

Heated arguments broke out between some protesters and AIPAC delegates entering the building. As tensions escalated, Mike Prysner, a journalist with TeleSur, was assaulted by an unidentified man who was admitted by police into the Convention Center immediately afterwards.

“This isn’t really a surprise,” Prysner said. “Every time I’ve been at one of these things, it’s the same thing every single time. The police have their backs at the people who are supporting Israel, and they have their batons toward the people who are supporting Palestine.”

According to Prysner, the man who allegedly assaulted him was arrested later.

Police chose not to arrest three protesters who broke through lines and held a sit-in at the entrance, blocking several doors. Ariel Gold, a member of Code Pink, said that she blocked the entrance to call out AIPAC as a supporter of apartheid.

“AIPAC advocates policies that are contrary to human rights,” she said. “We need to respect international law and universal standards for human rights and not fund the Israeli government which is an apartheid system.”

Palestinians want recognition of rights to remain on their land, to move about freely in their territory and to travel abroad. Other concerns revolve around access to electricity and clean water, as well as the ability to acquire construction materials to rebuild from attacks by Israeli Defense Forces.

“We are here to tell the whole world that Palestinians are human beings,” said Palestinian Jinan Deena, a volunteer with Al-Awda. “We deserve human rights just like everybody else.”

Elected officials, including the President and high-ranking members of Congress, accept invitations to speak at AIPAC’s annual conference every year. But presidential election years are a special measure of its influence, as candidates often make it a priority to attend and show their deference to the powerful pro-Israeli lobby. This year, Republican primary candidates Donald Trump, John Kasich, and Marco Rubio and Democratic primary candidate Hillary Clinton will address the convention. Democrat Bernie Sanders will not attend but will instead send written remarks.

American aid to Israel for military and economic growth is about $4 billion annually. Groups opposed to the aid say it comes at the expense of U.S. taxpayers and funds Palestinian apartheid through land grabs, demolitions of homes and illegal settlement building. In January, the European Union Foreign Affairs Council strongly condemned Israel for its settlement policies in the occupied Palestinian territories.