One person was on Thursday killed in a clash between Dera Sacha Sauda followers and Sikhs near Sunam in Sangrur district as tension mounted in Punjab after Sikh high priests called for a social boycott of the controversial religious group for allegedly insulting Guru Gobind Singh.

At least 22 people were injured in sporadic incidents of violence -- most of them attacks on Dera properties by Sikh protestors even as thousands of Sikhs laid siege to a Dera ashram in Salabatpura in Bhatinda district.

The Centre rushed paramilitary forces to Punjab and Sirsa in Haryana, where the Dera, which claims to have Sikh, Hindu and Muslim followers, has its headquarters. Its spokesman issued a veiled threat tonight that the Dera's supporters could not be kept in check if attacks on them in Punjab were not stopped.

Five high priests, who met at Talwandi Sabo Gurdwara near Bhatinda, gave the Punjab government time till May 20 to act against the Dera for its 'anti-Sikh activities.' After this period, Sikhs would be 'forced to act against the Dera,' they warned.

The Shiromani Gurdwara Prabhandak Committee, the apex religious body of Sikhs, was authorised to check activities of the Dera and its followers in Punjab.

Sikhs returning from the meeting at Talwandi Sabo allegedly damaged the boundary wall of a Dera property in Maur Mandi in Bhatinda district. No one was injured in the incident, ADGP (law and order) B Chandershekhar told PTI.

In Mansa, a chowk named after the Dera was demolished while a large number of Sikhs attacked a Dera property at Sunam in Sangrur district. Some persons were injured in this incident but no one was seriously hurt, he said.

Large numbers of Dera followers and Sikhs also came face to face near Salabatpur in Bhatinda district and police were present in strength to control the situation, he said.

Punjab police denied having issued any instructions for the vacation of Dera ashrams, a claim made by the group. Chandershekhar described reports on this issue on TV channels as a 'misinformation campaign' and said no such orders had been issued.

Police were taking steps to ensure the safety of a large number of Dera properties in the state, he said.

Dera head Gurmeet Ram Rahim Singh sparked a controversy by purportedly appearing in the attire of the 10th Sikh guru in an advertisement in some newspapers. Dera followers and Sikhs have clashed in Punjab, Rajasthan and New Delhi over the past three days.

Parts of Punjab and Haryana continued to be tense for the fourth day on Thursday due to the stand-off between Sikhs and Dera followers even as the government advised the governments of these two states and Rajasthan to keep security forces on alert.

Sikh protestors organised marches at several places, including Patiala, Karnal and Yamuna Nagar, and a partial bandh was observed in the Sikh holy city of Amritsar. The shutdown was complete in the walled city around the Golden Temple.

Leaders of the Dera, after a meeting held at headquarters at Sirsa in Haryana, expressed anguish at the call for a social boycott issued by the Sikh priests and said the move will divide society.

The Sikh high priests, who met under the chairmanship of the Jathedar of the Akal Takht, Joginder Singh Vedanti, finalised a five-point 'hukamnama' (edict). Following protests from a section of the large gathering of Sikhs, Jathedar of Takht Damdama Sahab, Balwant Singh Nandgarh, announced that the body had decided to give the state government an ultimatum to arrest the Dera chief by May 20 and to lock the Dera properties across Punjab.

Earlier at Talwandi Sabo when Vedanti read out the decisions, the Sikh gathering armed with weapons, including swords, started accusing the Takht chiefs of giving decisions mouthed by Chief Minister Prakash Singh Badal.    

Some among the crowd went wild and raised slogans against the decision. One of the followers of Damdami Taksal even threw a sword on Vedanti when he tried to come out of the stage. The sword, however, missed the mark.

In the border district of Gurdaspur, the AISSF took out a protest march in Batala and forced shopkeepers to close down their shutters and they held a demonstration in Gandhi Chowk.

Sikhs also protested against the Dera head in Lucknow with hundreds taking out a procession from Alambagh and later burning his effigy.

Police had to resort to baton-charge and fire in the air as hundreds of devotees returning from Talwandi Sabo attacked the Nam Charcha premises of Dera near Sunam.

According to unofficial sources, about nine persons were injured in the melee out of which four were referred to Rajindra Hospital Patiala in a serious condition.

Effigies of the Dera head were also burnt at Malerkotla, Barnala and village Bhalwan by various Akali outfits.