BOSTON (CBS/AP) – Hundreds gathered for a rally at Boston’s City Hall Plaza Sunday afternoon to pressure Congress to tighten the nation’s gun laws after the recent mass shootings in El Paso, Texas; Dayton, Ohio and Northern California. Gun-control advocacy group Everytown for Gun Safety has been organizing rallies over the weekend in every state.

They say 100 Americans are shot and killed every day, hundreds more are wounded.

Many mothers led the event, including Chaplain Clementina Chery, who lost her 15-year-old son Louis Brown in 1992 to gang crossfire. “Am I mad? Yeah, I am mad. Yet I am also encouraged so I will stand with you because I am a mom. I will continue to demand action,” she told the crowd.

Hundreds gathered at a rally in Boston to call for stricter gun federal gun laws (WBZ-TV)

Boston Mayor Marty Walsh attended the event. “This isn’t about taking people’s guns away, we’re not taking people’s rights away. That’s not what we are doing here and if anyone wants to disagree with that: listen to what we are saying. What we’re tired of is people being killed by guns. Illegal guns.”

Sen. Ed Markey also spoke. “I should not be here with you today,” he said. “I should be on the floor of the United States Senate right now in an emergency session to demand background checks on anyone buying a gun in the United States, to ban assault weapons in the United States.”

In Providence, Rhode Island on Saturday, demonstrators held signs that said, “Disarm Hate,” ”Enough” and “No One Needs a Weapon of War at Home.”

Activists are demanding a strong federal “red flag” bill to allow the seizure of weapons in certain cases and legislation requiring background checks on all gun sales.

Congress is on summer recess, but Republican Senate Majority leader Mitch McConnell has asked committee chairmen to review possible gun bills for consideration when lawmakers return in September.

Democrats on the House Judiciary Committee announced Friday that they will be returning early to consider other gun-violence legislation. The House has already approved legislation bolstering background checks for gun purchases.

The gunmen in El Paso and Dayton killed a total of 31 people in back-to-back weekend shootings in early August that stunned the nation and revived calls to tighten access to firearms. Those shootings came days after another gunman opened fire at a festival in Gilroy, California, killing three people.

(© Copyright 2019 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)