By Parisa Hafezi DUBAI, Jan 29 (Reuters) - Plainclothes Iranian security forces have rounded up thousands of people in a campaign of mass arrests and intimidation to deter further protests after crushing the bloodiest unrest since the 1979 Islamic Revolution,

Iran’s Islamic Republic, weakened by airstrikes in June and huge popular unrest, warns that it will strike back hard if attacked by the United States. This time, Iran may mean it.

From regime change to retaliation, the BBC's Frank Gardner outlines possible outcomes of US strikes on Iran.

Maritime intelligence warns of heightened risks for U.S.-flagged vessels in Persian Gulf as Iran threatens "immediate, all-out" response to any American military action.

The president advised Iran make a deal or "the next attack will be far worse."

He says a "massive Armada" is "moving quickly, with great power, enthusiasm, and purpose" towards Iran.

President Donald Trump runs hot and cold in his relationship with his Russian counterpart Vladimir Putin — often at the same time

Iran's bloody crackdown on nationwide protests killed at least 6,126 people while many others still are feared dead, activists said Tuesday, as a U.S. aircraft carrier group arrived in the Mideast to lead any American military response to the crisis.

Maliki's bid for Iraqi PM role as Secretary of State Marco Rubio expresses concerns about pro-Tehran government seizing control of Iraq.