The Department of Homeland Security is working with federal, state and local authorities to investigate the mass shooting in Monterey Park, California, according to a statement from the secretary of homeland security.

"We mourn the tragic loss of lives in Monterey Park, California. We pray for the full and swift recovery of those injured in the shooting," Secretary Alejandro Mayorkas tweeted. "The Department of Homeland Security is fully engaged with our federal, state, and local partners in responding to this horrible shooting."

"As a former United States Attorney for the California jurisdiction that includes Monterey Park, I know the community well and I feel the suffering of its residents very personally," Mayorkas added.

Four of the 10 victims are being treated at LAC+USC Medical Center, CEO Jorge Orozco said in a statement.

The hospital is a Level 1 trauma center "with medical personnel extensively experienced in providing exceptional care in gun related tragedies," the statement said.

Orozco declined to provide further details about the victims' conditions, citing HIPAA, the federal patient privacy law.

"However, we want to assure the families of those at our LAC+USC Medical Center that our medical teams are doing everything possible to care for their loved ones," the statement added.

Leaders across the country lamented the latest mass shooting Sunday as more information trickled out from authorities, with many politicians expressing solidarity with the Asian community.

Authorities have not released a possible motive in the shooting and have said it's too early to determine whether it was racially motivated as they search for a suspect.

New York Gov. Kathy Hochul tweeted that she was "heartbroken by the horrific shooting."

"At what should be a time of Lunar New Year celebration, the scourge of gun violence has struck yet another community — we must put an end to these senseless tragedies," Hochul said.

Also in New York, Senate Majority Leader Chuck Schumer, wrote: "We must stand up to bigotry and hate wherever they rear their ugly heads, and we must keep working to stop gun violence."

Rep. Katie Porter, D-Calif., called the incident a “tragedy,” adding that she is “keeping the victims and their loved ones in my thoughts, and I thank the first responders for their hard work.”

New York Attorney General Letitia James said: "New York is with you, and I’m praying for the families who lost their loved ones and for the recovery of those who were injured."

House Democratic leader Hakeem Jeffries of New York wrote that he was “deeply saddened and horrified” by the mass shooting, adding, “We must crush the rise of hatred and intolerance whenever and wherever it is found.”

Some called for swift action on gun control.

Rep. Jamie Raskin, D-M.d., called the shooting "another staggering heartbreak from the killing fields of gun violence, adding, "And let’s do what needs to be done in Congress, people. NRA, get the hell out of the way."

Sen. Bernie Sanders, I-Vt., said the shooting "is the latest horrible reminder that Congress must act boldly and NOW to protect our people from gun violence."

The University of Southern California's Pacific Asia Museum has canceled its Lunar New Year Festival planned for Sunday because of the Monterey Park shooting, it said in a statement.

The festival was meant to take place from 11 a.m. to 5 p.m. PT, featuring a lineup of cultural performances, the museum said on Facebook.

USC's Pacific Asia Museum, about a 20-minute drive west of Monterey Park, was established in 1971, and its mission is "to further intercultural understanding through the arts of Asia and the Pacific Islands," according to its website. The museum serves Los Angeles and Greater Southern California.

Vice President Kamala Harris spoke about the Monterey Park shooting in a speech Sunday in Tallahassee, Florida.

"I do want to address the tragedy that happened in my home state in Monterey Park, California," she said. "A time of a cultural celebration. And yet another community has been torn apart by senseless gun violence."

Harris said that "this violence must stop" and that she is praying for those who were injured and grieving for those "whose lives are forever changed."

"And President Biden and I in our administration will continue to provide full support to the local authorities as we learn more," she said.

Authorities said specific details about the firearm used in the attack remain sparse, but that they "don't believe it was an assault rifle" at this time.

"Different weapons had been described, in regards to the specific weapon, we don't believe it was an assault rifle at this time — but again, that part of the investigation we're looking at," Los Angeles County Sheriff Robert Luna said.

He added that there had been "multiple rounds fired" in Monterey Park, but that authorities hadn't yet determined exactly how many.

Authorities are looking into a seemingly similar incident in the nearby city of Alhambra that "may be related" to the mass shooting in Monterey Park, Los Angeles County Sheriff Robert Luna told reporters.

In that incident, which Luna said unfolded 17 to 20 minutes after the Monterey Park shooting, an armed Asian man walked into a dance hall before some of the dozens of people there wrestled the firearm away from him and he fled.

Authorities are considering a white cargo van described by some witnesses as "a van of interest," Luna said.

Alhambra is about 2 miles south of Monterey Park and also has a sizable Asian and immigrant population.

"Are they connected? Honestly, we don’t know the answer to that yet," Luna said of the incidents in the two cities.

Luna said local authorities are working with Alhambra police.

The 10 victims injured in the Monterey Park shooting are in "various conditions," ranging from stable to critical, Los Angeles County Sheriff Robert Luna told reporters Sunday.

Official said the investigation into the shooting will take "days if not months" as they continue to search for the suspect and analyze the incident.

The city of Monterey Park canceled the second day of its Lunar New Year Festival, slated for Sunday, "as a precaution and for the safety of everyone," the city's statement said.

Luna urged people to continue to celebrate Lunar New Year elsewhere.

Rep. Judy Chu, whose district includes Monterey Park, said she “can’t even imagine that such a thing would happen in this community.”

"I hope we can make a determination as to whether this was a hate crime," said Chu, who also served Monterey Park as a three-time mayor, according to her website.

“Monterey Park is resilient, and what I know about the people here is that we will get through this together," she said.

The suspect in the Monterey Park shooting who fled the scene and remains at large has been preliminarily described as an Asian male between the age of 30 to 50, Los Angeles County Sheriff Robert Luna said at a news conference Sunday morning.

"Our very preliminary description has been described as a male Asian," Luna said. "We’ve gotten different descriptions of one suspect, so when I say it’s preliminary, please be patient with us."

Luna said later that officials "should be putting out a better description here in next several hours."

"We don’t know if this is specifically a hate crime defined by law, but who walks into a dance hall and guns down 20 people? The description we have now is of a male Asian. Does that matter? I don’t know. I can tell you everything is on the table," Luna said.

The sheriff added that officials "are utilizing every resource to apprehend this suspect and what we believe to be one of the county's most heinous cases."