New York (CNN) -- New York police have stepped up patrols in a Staten Island neighborhood after a string of attacks on Mexican nationals, authorities say.
The attacks -- 10 since April -- are being investigated as "anti-Mexican assault cases," said Inspector Michael Osgood, head of the New York Police Department's Hate Crimes Task Force. The victims have all been Mexican males, police said.
In all but one case, the assailants were described as African-American, police Deputy Commissioner Paul Browne told CNN Wednesday. The victims typically have been beaten while assailants yelled racial slurs at them, he said.
Although the incidents vary, weapons -- including blunt objects, baseball bats and, in one case, a Razor scooter -- were used, police said. The assaults have resulted in multiple hospitalizations, authorities said. Browne said some victims were knocked unconscious. Five of the 10 were robbed, police said.
In the most recent attack, on Saturday, a 32-year-old man was struck in the chest with a baseball bat, knocking him to the ground, said police Sgt. Carlos Nieves. His assailants then kicked him in the face, Nieves said. The man was taken to a hospital, where he received 12 stitches across the left side of his face.
A total of eight people have been arrested in connection with three of the incidents, Browne said. In two of the three, the perpetrators are believed to be the same, a man and a woman, he said. The suspects range in age from 14 through the early 20s.
"We have increased patrols in the area," Police Commissioner Ray Kelly told reporters on Tuesday. "We're meeting with community people. We're meeting with our own officers internally, making sure we're doing everything we can do to prevent attacks such as this.
"We're concerned about it. We're not going to tolerate it. We're taking proactive measures to see to it that if it does happen, we're going to make an arrest very quickly."
Kelly met Tuesday with Ruben Beltran, Mexico's consul general in New York, said Beltran spokesman Julio Garcia.
A coalition of community organizations, elected officials and government agencies has launched a new initiative, I Am Staten Island, and a website, www.iamsi.info.
"This campaign was inspired by the spate of bias attacks that have taken place on Staten Island this year," the website says. "Initially, we thought that these were isolated, random incidents, but that no longer appears to be the case. Something very serious is happening on the island, and it is going to take a comprehensive response from the entire Staten Island community to address this challenge."
However, some community leaders have expressed doubt that whether the incidents were truly motivated by race. In two cases where arrests have been made, Staten Island grand juries have declined to indict the suspects on hate crime charges.
The victims might be undocumented and could be seen as competitors for scarce jobs, said Edward Josey, president of the Staten Island NAACP. "When the economy is bad and when jobs disappear, people get edgy," he said.
Meanwhile, Fernando Mateo, president of Hispanics Across America, said the incidents may be robberies, not hate crimes.
"Some of these cases are not racially motivated," he said. "They're motivated by people wanting to rob other people. When you're robbing someone, you might say slur words."
Browne said that usually, about 300 uniformed officers are stationed in the area. That number has been increased by about 100, he said. Kelly told reporters plainclothes officers might also be an option.
The Guardian Angels have also begun patrolling the Port Richmond neighborhood. Curtis Sliwa, president and founder of the volunteer group, said members began patrolling Monday and will continue "as long as needed."
"We welcome additional eyes and ears, whoever we can get," Kelly said.
Sliwa said his group's presence was requested by the Staten Island district attorney's office. The group, whose mission is to help prevent street violence and protect public safety, began patrols on Richmond Avenue Monday evening.
Hispanics Across America is offering a $5,000 reward for information on the assaults. A march is planned in Port Richmond Wednesday night by the nonprofit, primarily Latino group Make The Road New York.
CNN's Ashley Hayes contributed to this report.