Rail routes were disrupted and several trains stopped in Uttar Pradesh on Monday as the daylong shutdown against the hike in fuel prices began in the state, officials said.
"Samajwadi Party activists were detained in parts of the state for stopping trains and targeting public property," a police officer said.
Party workers took to streets in several districts. They also stopped several trains in Allahabad, Varanasi and Jaunpur.
"We have rounded up six Samajwadi Party workers near Phaphamau railway station for disrupting rail route and stopping the Ganga-Gomti Express train for some time," Additional Superintendent of Police SS Bhaghel told reporters in Allahabad, about 200 km from Lucknow.
"Additional security has been deployed at railway and bus stations. Security around prominent buildings and shopping complexes has also been strengthened," he said.
On Sunday, the Samajwadi Party joined the nationwide shutdown called by the Left parties and the BJP-led NDA to protest the price hike of petroleum products.
The central government ended government curbs on petroleum pricing and hiked the prices of diesel, kerosene and cooking gas.
The price of diesel went up by Rs 2 a litre, kerosene by Rs 3 a litre, petrol by Rs 3.50 a litre, and cooking gas by Rs 35 per cylinder.