Rail services between Tehran and Mashhad were suspended on Thursday after US strikes damaged rail infrastructure leading to Iran's holiest city, disrupting travel ahead of Ayatollah Ali Khamenei's burial .
The overnight attacks forced authorities to delay the late supreme leader's burial at the shrine of Imam Reza until 2:30 pm local time, Iranian state media reported, framing the strikes as an attempt to discourage attendance at the funeral.
Iran's Revolutionary Guards accused Washington of trying to "overshadow" the funeral and burial ceremonies by targeting key transport routes into Mashhad.
Iran's railway authorities said a section of the line linking Tehran and Mashhad was struck on Thursday morning, forcing the suspension of train services. Technical and operational teams were dispatched to repair the damage, with officials saying traffic would be restored "in the shortest possible time".
Hundreds of passengers were left stranded after services were halted, according to Iranian officials, who said "necessary arrangements" were being made to transport mourners to Mashhad in time for the burial.
Separately, the Fars news agency reported that overnight US strikes also damaged the Aq Taqeh Khan railway bridge in Golestan province, a key rail link connecting Iran with China and Russia through Turkmenistan and Kazakhstan.
Iran's foreign ministry condemned the attacks "in the strongest terms", accusing Washington of committing a "gross war crime".
The latest strikes marked the first time US warplanes had targeted Iranian bridges since April, when Washington expanded its campaign against the country's infrastructure.
On 2 April, a US double-tap strike on the unfinished B1 bridge in Karaj killed eight people and injured nearly 100, an attack Tehran also described as a war crime.
After leaving the NATO summit in Ankara on Wednesday, US President Donald Trump warned Iran: "This is in retribution for yesterday's bombing of ships by Iran. If it happens again, it will get much worse!"
His remarks came ahead of a second consecutive night of heavy bombing in the sharpest escalation since Washington and Tehran signed a memorandum of understanding in June.
Iranian authorities said at least 14 people were killed and 78 injured in the latest overnight strikes, with explosions reported across several provinces, including Bushehr, Hamadan, Mashhad and Khuzestan.
US Central Command said it struck around 90 Iranian military targets, including air defence and coastal surveillance systems, missile and drone depots, and naval facilities along Iran's southern coast.