Map of Syria.

Israelis lined up at gas-mask distribution centers Wednesday and communities bordering Syria readied bomb shelters as top government officials held emergency meetings amid fears of a possible Syrian attack on Israel. Israel also deployed additional missile defense systems near the country's border with Syria.

Supported by allies in the West, the U.S. has signaled that it may soon strike Syria in response to its alleged use of chemical weapons last week. That has raised speculation that Syria might retaliate with an attack on Israel, a close U.S. ally.