(AP) -- With a moment of silence, the tolling of church bells and a call for kindness, Boston marked the second anniversary of the marathon bombings Wednesday, the emotions clearly still raw from the devastating attack during one of this city's most cherished events.

On Boylston Street, people openly wept and hugged as church bells tolled at 2:49 p.m., the time the first bomb went off at the race's finish line April 15, 2013.

"It still feels like yesterday, to be honest," said Aleksander Jonca, a Boston resident who ran the marathon in 2013 and plans to run this year's on April 20. "Two years later I feel like we're still struggling to find the words to describe what happened that day."

Large crowds formed at the two roadside spots where the bombs detonated, killing three people and injuring 260 others.

Runners wearing Boston Marathon gear and bystanders with "Boston Strong" shirts fixed their eyes on the commemorative banners that had been revealed in a silent ceremony hours earlier.

More than 100 blue and yellow balloons - the marathon's colors - were released into a cloudless sky as the church bells faded.

"As a mom, I still haven't moved on," said Liz Norden, a Stoneham resident whose two adult sons - J.P. and Paul - each lost a leg in the attack. "I know my boys have moved on. But it's hard. I see them put on a leg every day. It's still raw."

At the Old South Church near the finish line, hundreds gathered for an interfaith service with Christian, Muslim and Jewish leaders who focused on healing.

"We turn now to acknowledge that life goes on," said the Rev. Demetrios Tonias, dean of the Annunciation Greek Orthodox Cathedral in Boston. "Living goes on. Our prayers go on. Our grief goes on. But so, too, does our resiliency go on."

Earlier Wednesday, Mayor Marty Walsh, Gov. Charlie Baker and bombing survivors unveiled commemorative banners marking the blast sites on Boylston Street with the plaintive wail of bagpipes in the background.

The orange banners, which were hung up on light posts, bear a white heart with a road receding into the distance and the word "Boston."

Elsewhere in the crowd, Jeff Bauman, who lost his legs above the knee in the blasts, exchanged a big hug with Carlos Arredondo, who helped save his life two years ago.

Bauman, who was able to describe to police one of the two brothers accused of carrying out the attack, also threw out the ceremonial first pitch later that day as the Boston Red Sox faced the Washington Nationals.

The afternoon game at Fenway Park was among the prominent locations people in Boston paused out of respect for the anniversary.

The mayor and the Richard family observed the moment at City Hall Plaza.

Baker and other top state officials formed a circle in Memorial Hall at the Statehouse.

"In many respects, those most affected by the events of two years ago have shown us all the way back - with their courage, grace and determination," Baker said in a statement. "They honor the past, remember and treasure loved ones lost and injured, and look forward to a better future. We should strive to do the same."

Walsh declared April 15 "One Boston Day," calling on Bostonians to embrace a new way of remembering the attacks.

People donated blood to the Red Cross and helped clean up neighborhood parks while schoolchildren wrote thank-you cards and delivered pizzas to police and fire departments in recognition for their service.

Next week, the federal death penalty trial of surviving bomber Dzhokhar Tsarnaev resumes.

The 21-year-old ethnic Chechen was convicted last week of 30 counts. Jurors will soon decide whether he should be sentenced to life in prison or to death.

Tsarnaev's older brother, Tamerlan, died following a shootout with police days after the attacks.