New Delhi/Gwalior/Alwar, Apr 2: At least nine persons were killed and hundreds injured today in violence across several states as protesters blocked trains, clashed with police and set fire to private and public properties, including police posts, during a nationwide bandh called by Dalit groups, officials said.

Thousands were detained following widespread incidents of arson, firing and vandalism across over ten states, several of them being BJP-ruled including Madhya Pradesh where at least six persons died during the protests against the alleged dilution of the SC/ST (Prevention of Atrocities) Act.

Two persons died in Uttar Pradesh and one in Rajasthan, according to officials there. Other states hit with violence included Punjab, Bihar, Jharkhand, Odisha, Gujarat, Haryana, Maharashtra and Delhi. Those arrested included a former BSP MLA in UP.

Curfew was imposed in several places, while the Union Home Ministry, which rushed 800 anti-riot policemen to MP and UP, asked all states to take preventive steps and maintain public order to ensure the safety of lives and property. The Army and paramilitary forces were also put on standby in Punjab.

In MP, the deceased included four Dalits and two upper caste Hindus, while several others were injured across the state, the officials said.

Inspector General (law and order) Makrand Deoskar told PTI that the casualties occurred during fights between the bandh supporters and its opponents and not due to police firing. A sub-divisional magistrate (SDM) and a police official were also injured in the protest in Gwalior-Chambal division, he said.

MP Chief Minister Shivraj Singh Chouhan appealed to the protesters to maintain peace in the state.

Transport, mobile and internet services were hit in many states with over 100 trains getting affected due to protests, even as the Centre moved the Supreme Court seeking review of its recent judgement on the SC/ST Act, maintaining that the verdict will violate constitutional rights of these communities.

The Supreme Court had on March 20 diluted certain provisions of the Scheduled Caste and Scheduled Tribe (Prevention of Atrocities) Act, in a bid to protect 'honest' public servants discharging bona fide duties from being blackmailed with false cases under the Act.

The verdict is being widely criticised by Dalits and the Opposition who claim that the dilution of the Act will lead to more discrimination and crimes against the backward community.

While some states had ordered the closure of educational institutions as a precautionary measure, incidents of arson, firing and vandalism were reported from various parts of the country and the properties facing the wrath of protesters included railway tracks, police stations as also public and private vehicles.

In UP, one person was killed in Muzaffarnagar and another in Meerut, while nearly 75 persons including 40 policemen were injured in violent protests in various parts of the state. Police have detained nearly 450 people there.

In Rajasthan, one person was killed and 26 others, including nine policemen, were injured in Alwar.

Home Minister Rajnath Singh appealed for peace, while Law Minister Ravi Shankar Prasad said the government was not a party to the Supreme Court decision on the SC/ST Act and "respectfully" did not agree with its reasoning behind the verdict.

Prasad said the government has filed a very comprehensive review petition in the matter.

Union Minister Ram Vilas Paswan, a prominent Dalit leader and head of NDA constituent LJP, appreciated the government's quick decision.

Senior Congress leader Ghulam Nabi Azad alleged that incidents of atrocities on Dalits and minorities have increased in the country since the NDA came to power in 2014, while AAP leader and Delhi Chief Minister Arvind Kejriwal extended his support to the protesting groups.

UP Chief Minister Yogi Adityanath appealed for peace and urged the people not to vitiate law and order, as violence was reported from many districts including Azamgarh where protesters torched two state-run buses, injuring several passengers.

Expressing her party's support to protests, BSP supremo Mayawati alleged that some anti-social elements instigated violence leading to loss of lives and damage to properties.

The CBSE postponed Class 12 and Class 10 examinations scheduled to be held today in Punjab.

In the national capital region, protesters squatted on tracks at several places stopping trains, while protesters shouting slogans of 'Jai Bhim' also blocked roads affecting traffic movement, police said.

In Patna, protesters stormed the railway station, forced closure of ticket counters and squatted on tracks disrupting the movement of a number of trains.

Normal life was also affected in several parts of Odisha where activists of different Dalit groups put up road blockades. Thousands were arrested across Bihar, Jharkhand and Odisha, while the impact was minimal in West Bengal through its Chief Minister Mamata Banerjee expressed her support for the Dalit cause.

Major towns and cities of Gujarat also witnessed protests while civic-run transport services were halted after some of the buses were targeted by agitators.