The nation's mayors — and one mother running for Uvalde mayor after her daughter was killed in the 2022 mass shooting at Robb Elementary — offered condolences and called for gun reform as the search for the Maine shooter continued.

Mayors of hundreds of American cities and towns have faced the nightmare of mass shootings, and city leaders who have been through it before took to social media in solidarity with the mayors of Lewiston and Auburn, even as their communities remained under lockdown as police attempt to find the suspected gunman.

Police extended shelter-in-place orders for thousands of residents across southern Maine, as authorities searched for Robert Card, a suspect in the two deadly shootings that killed 18 people Wednesday evening.

Speaking for the U.S. Conference of Mayors, the mayor of Reno, Nevada, Hillary Schieve, said the Maine mass shooting is "a reminder of the serious consequences resulting from the easy availability" of weapons in the United States.

“America’s mayors stand with Lewiston Mayor Carl Sheline, Auburn Mayor Jason Levesque, and the residents of Lewiston, and all of Androscoggin County as they shelter in place awaiting news about the victims, praying that they are not family members or friends," Schieve said.

"While some say this isn’t the time to call for stronger gun laws, we believe this is exactly the time to do so," she said, adding that Congress should "enact an assault weapons ban, a ban on high-capacity magazines and universal background checks."

Here's what other mayors around the country had to say:

'Broken hearts' in Texas towns that have faced mass shootings

El Paso suffered the deadliest attack on Hispanics in modern memory on Aug. 3, 2019, when a gunman entered a busy Walmart near the U.S.-Mexico border and fatally shot 23 people. Two dozen more were wounded in the racist killing targeting Mexican Americans and Mexican nationals.

“Our hearts are broken again as now Maine deals with a senseless and horrific act of violence," El Paso Mayor Oscar Leeser said in a statement. "As a city that has gone through this, we can share that there is no way to understand this type of hatred. We stand in solidarity and support with Lewiston, and we will always encourage tolerance, empathy and kindness in our communities.”

In Uvalde, the mother of a 10-year-old girl killed in the May 24, 2022, Robb Elementary School shooting, is campaigning to become mayor. Kimberly Mata-Rubio lost her daughter Alexandria "Lexi" Rubio and told ABC News in August that she is running to honor her daughter's legacy and “to be the change I seek.”

Nineteen 3rd and 4th graders and two teachers died in the school shooting.

"My heart is broken for Maine," Mata-Rubio said on X, formerly Twitter, alongside juxtaposed headlines on Maine's permissive gun laws.

Days after the El Paso mass shooting, a gunman killed seven people in the Midland-Odessa region of Texas. He wounded 25 others, including three police officers. Police fatally shot the shooter outside a movie theater in Odessa.

"I’m truly heartbroken by the tragedy in Maine," said Odessa Mayor Javier Joven in a statement. "This devastating event underscores the urgent need for us to come together to find solutions and prevent such senseless violence."

More:Rampage in Maine is the 36th mass killing this year. Here's what happened in the others

Big city mayors call for stricter gun laws

The mayors of New York City, Atlanta, Baltimore and Albuquerque all called for gun reform.

In New York, Mayor Eric Adams said news of the Maine was "devastating."

"We don’t have to live like this, and we definitely don’t have to die like this," he said in a post on X. "Tonight, we must do more than mourn. We must resolve to take real action."

Atlanta Mayor Andre Dickens said he and other mayors have been calling on Congress to pass "commonsense gun laws."

"Time and time again, we have seen needless loss of life because of the deadly combination of mental health issues and ease of access to guns," he said in a statement.

Albuquerque Mayor Tim Keller said his community is "infuriated by the mass shooting in Maine, and we are keeping the entire Lewiston community in our prayers."

"We cannot let these horrific acts of violence continue to be the norm," Keller said. "We need action on gun violence now."

Baltimore Mayor Brandon Scott said: "It's the guns."

"It's the ease of access for people who should not have them," he said on X. "It's the mental health aspect. But most of all, it's our country's failure to address the issue as a nation. We all are praying for Lewiston. But we know that prayers are not enough and want national action."

There have been 569 mass shootings in the United States since 2006, according to a database maintained by USA Today in partnership with The Associated Press and Northeastern University.

Lauren Villagran can be reached at [email protected] or on X, formerly Twitter, @laurenvillagran.