Young men vandalised trains, damaged buses and torched a police outpost on Friday as they protested over the Centre's Agnipath scheme at several places in Uttar Pradesh.
Officials said protests took place at 17 places across the state, including Ballia, Aligarh, Gautam Buddh Nagar and Varanasi.
Protesters set a rail coach on fire in Ballia, where police lobbed teargas shells to disperse them and took 100 people in custody.
In Aligarh's Jattari, a group of protesters set a police vehicle and outpost on fire.
A police official was injured during a protest over the scheme there. Jattari is on the highway connecting Aligarh city with the Yamuna expressway.
The Aligarh police detained 30 people while an FIR was lodged against more than 150 protesters in Gautam Buddh Nagar district, according to officials.
A flag march was also conducted by police in Aligarh.
Several trains were cancelled or held back by the Railways to prevent damage.
Additional Director General of Police (Law and Order) Prashant Kumar said arson was reported from Ballia and Aligarh.
In Ballia, youths set a bogie of an empty train on fire, he said.
A video showed some youths raising slogans and vandalising the Ballia-Varanasi-Memu and Ballia-Shahganj trains.
They also threw stones near a railway godown and targeted private shops at the railway station platform.
Ballia Superintendent of Police Raj Karan Nayyar said, "Some students while returning from the railway station tried to smash the windowpane of an empty train and set on fire a bogie."
District Magistrate Saumya Agarwal said around 100 people have been taken into custody.
"They were identified using CCTV footage and strict action will be initiated against the accused. The situation is under control," he said.
Ballia MLA and state Transport Minister Daya Shankar Singh's brother Dharmendra Singh said unruly elements threw stones at the camp office of the leader and also damaged the hoarding put up at the office gate.
District Inspector of Schools Rakesh Kumar has ordered that schools will be opened after vacations only after further orders.
ADG (Law and Order) Prashant Kumar said Circle Officer Khair Indu Siddhartha was injured in the protest in Aligarh.
"He is well. I spoke to him personally. He sustained minor injuries but he is continuing his duty like a brave policeman," he said.
A bus was set afire on the Yamuna Expressway near Tappal in Aligarh and at least two others damaged.
"Thirty miscreants who allegedly indulged in violent protests in Aligarh have been detained by police and FIR is being lodged under various provisions of the law," said SSP Kalandidhi Naithani, adding that peace has been restored in the district.
Four buses were damaged in stone pelting on the Agra-Lucknow Expressway in Firozabad. SP (Rural) Akhilesh Narayan said the protesters in Matsena set up barriers around 7 am and stopped buses.
"The passengers were provided with alternative buses," he said, adding that the accused are being identified.
In Varanasi, youths raised anti-government slogans at the cantonment railway station and damaged buses and carts.
Youths also damaged buses outside the DRM office in the Lahartara area of the city. Police Commissioner A Satish Ganesh said an appeal has been made to protesters to maintain peace.
Protesters also disrupted traffic on the Agra-Gwalior highway.
They pelted with stones the vehicle of the Malpura police station SHO in Agra. Thereafter, they hurled stones at a train near the Bhandai railway station.
SP (West) Satyajeet Gupta said no one was hurt in the accident.
In Gautam Buddh Nagar, over 150 people have been booked in connection with the protest on the Yamuna Expressway, police officials said. Seventy of them have been named in the FIR, they said.
Scores of youngsters also descended on the Yamuna expressway and blocked traffic briefly near Jewar, officials said.
Vehicular movement through the Jewar toll plaza between Greater Noida and Mathura-Agra was blocked for around an hour from 12 pm, they said.
In Amethi, youths blocked the roads to Durgapur and Pratapgarh.
In Unnao, youths protested in Safipur near Mahatma Gandhi Inter College. They handed over a memorandum to the SDM addressed to the defence minister. They also took out a bike rally and raised slogans.
Unnao SSP Shashi Shekhar said the protesters were explained the new recruitment scheme and sent back.
As protests snowballed, the Railways cancelled some trains while they stopped a few others.
North-Eastern Railways spokesperson Pankaj Singh told PTI that 12 trains were cancelled.
These are Varanasi-Chhapra, Chhapra-Aurihar, Ballia-Varanasi, Azamgarh-Varanasi, Prayagraj Rambagh-Mau, Mau-Prayagraj Rambagh, Thave-Chhapra Kacheri, Chhapra-Varanasi, Thave-Masrakh, Masrakh-Thave, Varanasi-Ballia and Banaras-Patna Express.
Another 15 trains have been stopped at various railway stations and services will resume once the situation improves, he added.
The Centre on Tuesday unveiled the ambitious scheme for recruitment of the youth aged between 17 and a half and 21 in the Army, Navy and the Air Force, largely on a four-year short-term contractual basis.
The youth recruited under the scheme will be known as 'Agniveers'.
After the completion of the four-year tenure, 25 per cent of the recruits from each specific batch will be offered regular service.