OAKLAND (CBS SF/AP) — New Oakland Police Chief LeRonne Armstrong returned to Chinatown late Thursday, walking the streets he once patrolled as a beat officer, assuring local residents that security has been heightened in the district in the wave of attacks on elderly victims.

Friday marks Lunar New Year — generally a time of celebration throughout the Asian-American district — but this year the attacks have local residents –particularly the elderly — fearful for their safety.

In just the last two weeks, authorities recorded 18 crimes against Asian Americans around Oakland’s Chinatown, according Alameda County District Attorney Nancy O’Malley. She has launched a special unit within her department to investigate the attacks.

To counter the surge in violence, Armstrong has deployed the department’s mobile community command unit to Chinatown and increased police street patrols. He also took the streets to personally assure residents and business owners that his department was there to protect them.

“We wanted our business owners and community to know that we care,” Armstrong said. “That we are concerned and are going to do everything to keep the community safe.”

RELATED: Oakland Chinatown Attacks

Officials also have visited San Francisco Chinatown this week to address residents’ safety concerns and condemn the violence. They vowed to combat a problem that has been simmering since the start of the coronavirus pandemic but sparked new outrage after two unprovoked attacks were caught on video within a span of days and spread widely online.

In one, a young man shoved Vicha Ratanapakdee to the ground on Jan. 28 as he was taking his morning walk in San Francisco’s Anza Vista neighborhood. The 84-year-old Thai man’s head struck the pavement, and he died two days later in a hospital. Prosecutors charged a 19-year-old with murder and elder abuse.

On Jan. 31, a security camera caught a man in a hooded sweatshirt barreling into a 91-year-old Asian man in Oakland’s Chinatown, causing him to fall face-first into the pavement, narrowly missing a bike rack. Police arrested the suspect and said he had assaulted a couple on the same block later that day and another on Feb. 1.

Community advocates said the attacks have left many older Asians fearful about going out to shop for Friday’s start of the Lunar New Year, the most important holiday in several East Asian countries that marks the beginning of the Chinese lunar calendar. Shops and restaurants are typically bustling in Chinatowns this time of year, but the pandemic and safety concerns have dampened the festive atmosphere.

“There’s a huge amount of sadness and rage in the community,” said Alvina Wong, director of the Asian Pacific Environmental Network. “Folks are on edge and tense and don’t know when the next thing is going to happen. They see what’s happening in other cities, and it’s not stopping.”

The recent attacks represent the latest spike in verbal and physical attacks against Asian Americans since the coronavirus, which emerged in China, reached the United States. Stop AAPI Hate, launched by two advocacy groups to encourage Asian Americans to report such incidents, has documented more than 3,000 attacks to date.

O’Malley said older Asians are targeted because of the stereotype that they don’t report crimes due to language barriers. Her office is investigating whether the attacks were racially motivated and has launched a special response unit focused on crimes against Asian Americans, especially older Asians.

She said her team will focus on outreach and encourage victims to report crimes.

“For many of the seniors, it’s not part of their nature or culture to call the police. Some of them come from countries where you do everything to avoid the police,” the prosecutor said. “So the more they meet with us and understand our culture, the more people will open up to us about what’s been happening to them.”

Meanwhile, the attacks have prompted volunteers to offer to walk older residents to their cars or homes after shopping.

Jacob Azevedo said more than 200 people signed up after he posted on social media the idea of an on-call buddy system to chaperone residents who feel unsafe walking alone in Oakland’s Chinatown. They also donated thousands of dollars to help him buy a personal alarm device that will be distributed to older Asians in the community.

“The only way that we can help people and stop this from happening is if everyone steps in,” he said.

Azevedo said he intends to keep the program going “as long as old people don’t feel safe and people are taking advantage of a vulnerable group like that.”

© Copyright 2021 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.