An explosion killed at least two people and injured dozens more near the Italian city of Bologna in an incident that caused a bridge to partially collapse.
Video footage and photos posted on social media showed a massive explosion, fireball, and smoke.
The windows of many houses were shattered by the explosion, ANSA also reported.
Some people were reportedly hit by flying glass as windows shattered in nearby buildings.
Officials did not immediately know what kind of materials were in the tanker, but the news agency ANSA said it was liquefied petroleum gas.
The explosion reportedly came after a traffic accident. Videos show flames shooting up in the air after the explosion, replaced later by a thick black cloud of smoke. Aerial photos showed a gaping hole in the raised highway next to the tanker.
Authorities said a major highway interchange had been closed north of the city due to the accident. The interchange connects two major highways linking northern Italy with the Adriatic coast, a popular destination as Italy heads into its major summer holiday next week.