A US-Israeli strike on the B1 bridge in Alborz province killed two people and wounded a number of residents and tourists, the provincial governor's office said on April 2.

The bridge, described as a "masterpiece of Iranian engineering," was nearing completion and was due to open shortly connecting Karaj to the new "North" highway. The bridge would shorten the travel time to the capital city area to the north of Iran by more than an hour.

The deputy political-security governor of Alborz, identified as "Seif," said the unfinished structure had been damaged and urged residents to avoid the area. The strike occurred on a national holiday called "nature day", which is celebrated by most families with time in green areas and parks. 

Following the hit on the structure, Iran said bridges across the region had become “legitimate targets.” Including the Arik Bridge on Route 87 in northern Israel, which connects the Lower Galilee to the Golan Heights, Ynet reported.

The targeting of a civilian infrastructure project with no military function drew immediate backlash. An Iranian hacker group responded by threatening to attack the Sheikh Zayed Bridge in Abu Dhabi, one of the UAE's most iconic structures, in retaliation.

The threat signals a widening of the tit-for-tat targeting logic beyond military assets to prestige infrastructure projects.

The strike on the B1 bridge fits a pattern of US and Israeli forces targeting civilian infrastructure that Iran says has no military purpose. Tehran has accused Washington and Tel Aviv of deliberately hitting economic and civilian sites to weaken public morale and degrade the country's industrial capacity.

Strikes have hit steel plants in Khuzestan, Isfahan and Chaharmahal and Bakhtiari province, a Red Crescent pharmaceutical factory, power substations and the chamber of commerce headquarters in central Tehran.

Iran's Ministry of Health has reported more than 2,076 people killed since the war began on February 28, including 216 children. Trump said in his primetime address on April 1 that US forces would hit Iran "extremely hard" for another two to three weeks and threatened to destroy all of the country's power plants if no deal is reached.