The head of the security network for U.S. Jewish organizations said the community is "standing vigilant" following deadly bombings at the Boston Marathon.
A second incident at the John F. Kennedy Presidential Library in Boston, initially thought to be related, was mechanical fire, police said.
At least three people were killed and more than 138 injured in two blasts at the marathon on Monday, according to reports. One of the bombs exploded at the finish line.
A New York Post report, unverified by authorities as of Monday evening, said a 20-year-old suspect in custody at a Boston hospital is a Saudi Arabian national. Fox News said the suspect has severe burns. No other news sources as of Monday evening were reporting information about a suspect. Boston Police Chief Edward Davis said at a press conference Momday night that no suspect was in custody, but police were "talking" to an individual about the crime.
"We know that unfortunately 30 percent of terrorist attacks had Jewish institutions as secondary targets," said Paul Goldenberg, director of the Secure Community Network. "However, I must stress that there is absolutely nothing here that indicates any connection to an attack on the Jewish community. But based on history, we are standing vigilant for at least the next 48 hours."
He said the attacks appear to be extremely well planned.
In a brief statement Monday afternoon President Barack Obama said "We still do not know who did this or why .. but ake no mistake. We will get to the bottom of this. Any responsible individuals, any responsible group will feel the full weight of justice."
The Combined Jewish Philanthropies of Boston and Jewish Community Relations Council of Boston expressed sympathy to the victims and their families. "Our thoughts and prayers go out to the Greater Boston community, courageous runners, family, friends and those visiting from the United States and abroad," the organizations said in a statement.