The man died during treatment at a hospital in Kandivli. (Representational)

A man died and a woman accompanying him suffered severe burn injuries after some people threw acid at them on the Mumbai-Ahmedabad highway in Palghar, the police said today.

The incident occurred on Tuesday night when the two were on their way to Dahisar, a northern suburb of Mumbai, the police said.

The man was identified as 41-year-old Avinash Tiwari, they said.

"After having dinner at a hotel on the highway, the duo was returning to Dahisar on a motorcycle. When they were waiting to cross the road at Versova bridge near a petrol pump, some unidentified people attacked them with acid," senior inspector of Valiv police station, Vilas Chowgule, said.

Mr Tiwari, who suffered grievous injuries in the attack, died during treatment at a hospital in Kandivli, he said, adding that the woman, 38, was being treated.

The motive behind the attack is yet to be known, the police said.

An offence under IPC sections 302 (murder), 307 (attempt to murder) and 326A (voluntarily causing grievous hurt by use of acid, etc) was registered, the police said, adding that a search has been launched to find the accused.