DEBKAfile's exclusive sources in Tehran report:

Little credence is given in Tehran to the official claim that the colossal train explosion which killed at least 300 people and razed five villages in the northeastern Khorassan province Wednesday was caused by colliding wagons carrying industrial chemicals and fertilizers, as well as diesel fuel and cotton. Such flammable freights are usually shipped separately in Iran.

DEBKAfile’s sources note that Iranian officials, two days before a highly controversial parliamentary election, are doing their best to play down the disaster outside Neyshabur which rocked houses 50 miles away in Mashad. The Islamic Republican News Agency tried to blame an earth tremor of 3.6 magnitude, but the US Geological Institute in Colorado said no seismic activity was recorded in the area.

Most of the dead were fire and rescue workers, but also the city’s governor Mojtaba Farahmand-Nekou, its mayor and fire chief.

DEBKA’s sources in Tehran have heard unconfirmed reports that the disaster was no accident, but possibly sabotage carried out by anti-government forces in Khorassan province, which borders on Afghanistan. This report ties in with another that claims the train was not carrying innocent industrial cargoes but hundreds of tons of explosive materials Iran was smuggling into Afghanistan via the Shiite city of Herat to be used by Iranian saboteurs and agents for guerrilla attacks on US troops and the forces of President Hamid Karzai, as well for supplying the Taleban in their Kandahar stronghold.

DEBKAfile’s sources report that there were a series of blasts; the first inside the Neyshabur train station was powerful enough to trigger a second explosion in the remote station of Khayyam. There, it set ablaze another train carrying fuel and other flammable material.

Iran has long used Khorassan province as a conduit for smuggling thousands of its agents into Afghanistan. But the province is also home to nearly two million Afghan refugees, some of whom hire out as agents to the Kabul government or the US military. The suggestion is that a group of these agents were ordered to blow up the train when it pulled into Neyshabur. Their mission: to deter the Iranians from further meddling in Afghanistan.

It would not have been hard to persuade Afghan refugees to undertake the mission. As Sunni Muslims, they harbor strong feelings of resentment against their discrimination at the hands of Iran’s Shiite majority. Three years ago, Afghans were responsible for a large explosion in Mashad, an attack launched after Iran ordered the destruction of a makeshift mosque the refugees had built. Several weeks later, a similar blast occurred in Zahedan, capital of Iran’s Baluchestan province, where Iranian authorities had pulled down another mosque constructed by the refugees.

It just so happens that in the historic town of Neyshabur, site of Wednesday’s horror, the 11th century poet Omar Khayam was born and buried.