BHOPAL, India – Thousands of survivors of the world’s worst industrial accident blocked trains through a central Indian city on Saturday to demand more compensation.

The protest came on the 27th anniversary of the disaster in Bhopal, where a Union Carbide pesticide plant leaked lethal gas that killed an estimated 15,000 people and maimed tens of thousands more.

Activist Rachna Dhingra said police charged the protesters with sticks in trying to stop them from occupying Bhopal’s five train lines. The protesters, most of them women sitting on the tracks, threw stones at the officers and set four police jeeps and several motorcycles on fire.

Several people, including a police superintendent, were injured in the stone pelting, police said. Eight women were detained, activists said.

Trains were backed up and halted on most lines through much of Saturday.

The five Bhopal victims’ rights groups that organized the protest demanded that Dow Chemicals, which bought Union Carbide in 2001, pay $8.1 billion in compensation for more than 500,000 people exposed to the leak.

The activists called off plans to continue the protest today, after the chief minister of Madhya Pradesh state, where Bhopal is located, promised to back their campaign and lobby the prime minister for his support.

The protesters – shouting slogans including “We want compensation” – said India’s government accepted far too little in a 1985 settlement for $470 million, after initially asking for $3.3 billion.

The government is seeking an additional $1.7 billion for the victims from Dow, and activists accuse the U.S. company of not cleaning up oil and groundwater contamination in Bhopal.