Rebuilding Iran's B1 bridge near Karaj, hit by nine missiles in a US airstrike on April 2, will cost about $11.7mn, Hooshang Bazvand, managing director of the Construction and Development of Transportation Infrastructures Company, said on September 21, Iranian Students' News Agency (IUSNews) reported.

The unfinished cable-stayed structure, at about 136 metres, the tallest bridge in the Middle East, carries the northern Karaj bypass and became one of the most visible civilian targets of the seven-month war.

At least eight people were killed and 95 wounded in the strike, some of them family members marking the Sizdah Bedar holiday in the valley below, in an attack experts have said may breach the Geneva Conventions.

"After the bombing at five in the afternoon on April 2, at around six an American drone came and targeted the bridge's cables so that the bridge would collapse, but that did not happen," Bazvand said.

Around nine missiles hit the area, and engineers had to establish whether the piers had been damaged, he said. The rebuild has gone to the original contractor without tender because it knew the structure, and replacement cables were ordered from abroad.

"In these wars, the enemy's first action after targeting military sites and infrastructure was to attack transport infrastructure," Bazvand said. "The first corridor that was bombed and destroyed was the Tehran-Khuzestan route, and almost all the bridges on it were destroyed, and a number of tunnels were also hit."

Tunnels and bridges around Pol-e Zal in the Zagros range were bombed, he said. "Despite this destruction, no problem arose for the country. Nothing happened that would leave the country stranded, and the Khuzestan corridor was not blocked for more than 20 days. Diversion routes were created, and our colleagues worked round the clock."

The Tehran-North freeway and the Pardis road were also targeted, "but fortunately the missiles did not function and did not detonate", he said. A US strike on a railway bridge near Turkmenistan cut the China-Russia freight corridor.

On the 162 km Rasht-Astara railway, Bazvand said land acquisition is complete, though some farmers have not been paid. Moscow wants Iran's parliament or Supreme National Security Council to ratify the agreement before an implementation contract is signed.

"I think within a few months at most the council will settle the question of implementation and decide whether this project is carried out with the Russians or by ourselves."