The United States and Iran exchanged attacks for a second straight day, raising fears of a renewed full-scale conflict across the Middle East.

The latest U.S. strikes, which continued into Thursday morning in Iran, appeared broader and more intense than the previous day's operation. Iranian authorities, however, provided few details regarding the extent of the damage. Meanwhile, an Indian official reported that a U.S. strike on an oil tanker accused of breaching Washington's blockade of Iranian ports killed three Indian sailors, highlighting the growing risks faced by maritime workers in the region.

The latest hostilities marked the third major exchange of fire in the region this week. The violence began with clashes between Iran and Israel and was followed by two rounds of attacks between Washington and Tehran, affecting several countries that host U.S. military facilities.

The escalation comes as diplomatic efforts to end the conflict remain deadlocked. U.S. President Donald Trump warned that Iran would "pay the price" if negotiations continued to stall. In response, Iran's Foreign Ministry said Thursday that recent U.S. attacks had "effectively rendered the ceasefire meaningless," though it stopped short of announcing a formal withdrawal from the agreement.

A key issue in the negotiations remains Iran's control over the Strait of Hormuz, a critical shipping route whose disruption has affected global energy markets, increased fuel costs and contributed to rising prices for essential goods worldwide.

Iran announced on Thursday that the strait had been closed, although the practical implications remained uncertain. Maritime traffic has already been severely restricted since the outbreak of the conflict, with only limited shipping activity continuing through the waterway. U.S. Central Command rejected Tehran's claim, while Trump stated that the U.S. had been conducting a covert operation in recent weeks to move vessels safely through the strategic passage.

Another major sticking point remains Iran's nuclear programme. Tehran maintains that its nuclear activities are intended solely for peaceful purposes, while the United States and Israel argue that Iran's stockpile of highly enriched uranium could potentially be used to develop nuclear weapons. Both Washington and Tel Aviv have cited this concern as a primary reason for launching military operations against Iran on Feb. 28.