Nadler condemned the attacks, which were described in press reports as "coordinated" against civilian and military targets that also wounded 20 others. The attacks took place near the Israel-Egypt border. Nadler reiterated that the U.S. must continue to support Israel's fight against terrorism.

"This attack, as barbaric as it was, must not be viewed in isolation," he said. "It is part of a long-term threat to Israeli civilians by determined terrorists.  I hope that Israel's critics will take note."

Nadler was one of several members who commented on the attacks. Rep. Steve Rothman (D-NJ) said they show the importance of ensuring that the borders bewteen Israel, Egypt and Gaza are "fully monitored and secured."

"Clearly, Egypt must take greater steps to prevent terrorists from crossing its border," he said.

House Minority Whip Steny Hoyer (D-Md.) said in a separate statement that "America stands by Israel in the wake of these attacks, and we must do all we can to prevent such attacks from happening again."

-- This story was updated at 4:16 p.m. to add reactions from Rothman and Hoyer.