Thai police blasted protesters with water cannon and used teargas on Tuesday, hurting several people in a bid to push back a demonstration at Parliament demanding constitutional changes that would touch on the powerful monarchy.

Protesters are demanding changes to the constitution drawn up by a former junta. They also want the removal of Prime Minister Prayuth Chan-ocha, a former army ruler, and are calling for reforms to curb the powers of King Maha Vajiralongkorn.

Police sprayed water cannon at protesters who tried to cut their way through razor-wire barricades. Then they fired teargas at the hundreds of demonstrators.

Ambulances...