Rafah, Egypt - Egypt began work to seal off smuggling tunnels into the Gaza Strip on Tuesday, a security source said, two days after gunmen shot dead 16 Egyptian border guards in an attack blamed partly on Palestinian jihadi militants.

As officials weighed how to strike back after the deadliest assault along Egypt's tense Sinai Peninsula frontier with Israel and Gaza in decades, crowds of angry mourners wept at the military funeral for the slain guards in Cairo.