Iran has placed its military forces on high alert, fearing an attack from the United States and Israel.
"They [Iranian authorities] are just waiting for the attack and are anticipating it every night and everything has been on high alert — even in sites that no one knows about," one source told the Telegraph.
Since the terrorist attack against Israel in October last year, Israel has staged a number of attacks against military and nuclear production sites in Iran and against proxy organizations in the region.
A full-bore combined U.S./Israeli attack would be significantly different, however.
The source quoted by the Telegraph said, "Recent developments, including [President] Donald Trump's comments and reports about potential plans from his administration to strike Iran, have further intensified activities."
A report carried by Newsmax in early February pointed out comments by Trump that he would like to arrive at a tension-easing diplomatic deal between the U.S. and Iran.
Trump increased pressure on Iran this month by imposing a campaign of maximum pressure with sanctions against Iran's oil production and even ships that transport oil from Iran in an attempt to cut Iran's exports as low as possible.