San Francisco police are on alert and Muslim leaders in the Bay Area are denouncing the terror attacks that left 49 people dead and more wounded in New Zealand.
"We mourn the heartbreaking killings of men, women and children gathered for prayer in their houses of worship," said Ammad Wajahat Rafiqi, a civil rights and legal coordinator for the Council on American-Islamic Relations' Bay Area office in Santa Clara.
Rafiqi also asked for support from other leaders.
"...(We) urge leaders in our nation and worldwide to speak out forcefully against the growing anti-Muslim and anti-immigrant hate that appears to have motivated growing white supremacist attacks against vulnerable communities such as Muslims, Jews, Sikhs and African-Americans," he said.
A gunman opened fire at two different mosques in New Zealand during prayers on Friday, killing 49 people. Many more were wounded.
Authorities also found explosives attached to a vehicle, according to national media reports. A suspect has been arrested.
In the United States, authorities were posted outside mosques. San Francisco police officers are doing extra passing calls around mosques in the city, according to spokesman Joseph Tomlinson.
"It's a precautionary measure," Tomlinson said. "We want to at least be aware."
Rafiqi also suggested Muslim organizations step up their own security following the attacks.
"In the wake of this tragedy, we urge mosques, Islamic schools and other community institutions in the United States and around the world to take stepped-up security precautions, particularly during times of communal prayer," he said.
Rafiqi said community leaders are expected to hold vigils for the victims this weekend in the East Bay, Peninsula and San Francisco. Details on those events weren't yet available Friday morning.