Jerusalem, Sept. 29 -- Israel has placed its security forces on heightened alert following the United Nations' decision to reimpose sweeping sanctions on Iran under the snapback mechanism of the 2015 nuclear deal, amid concerns Tehran may accelerate its nuclear programme.

The sanctions, reinstated on Sunday after the UN Security Council rejected a Russia-China bid to delay them, restore restrictions on arms sales, uranium enrichment and ballistic missile activity, along with asset freezes and travel bans on designated individuals.

While the sanctions mark a diplomatic victory for Israel and its allies, officials have warned that the move could also embolden hardliners in Tehran who might respond by accelerating enrichment activities or te...