Iran has threatened to strike Israel, US military bases and shipping if Washington attacks, reported Bangalore's Marine Insight.

The warning also heightened concerns for regional maritime security, as Iran said shipping in the Middle East would be treated as a legitimate target if hostilities escalate.

Parliament speaker Mohammad Baqer Qalibaf issued the warning during a televised session, saying Iran would retaliate immediately if attacked. Lawmakers were seen chanting anti-US slogans as protests against the government entered a second week despite an internet shutdown.

Human rights groups said security forces were using lethal force, with hundreds of protesters reported killed. The US-based Center for Human Rights in Iran said hospitals were overwhelmed and many demonstrators had been shot in the eyes, calling the tactic deliberate.

President Donald Trump is weighing possible military action, raising fears of wider conflict. Israel has placed its military on high alert amid concerns that any US strike could trigger Iranian retaliation.