The Punjab Police registered a case against Shiv Sena's Delhi unit president Jai Bhagwan Goyal and would investigate party supremo Bal Thackeray's role in Thursday's incident at the Punjab Cricket Association stadium in Mohali.

Addressing a press conference on Friday, DIG of Ludhiana Parag Jain and Senior Superintendent of Police of Ropar S P Singh said the police would seek arrest warrants against Goyal, claiming that he was the "mastermind" behind the incident, after the six Shiv Sena activists, who were arrested last evening, detailed his role in it.

"The role of [Bal] Thackeray would be ascertained," Jain said, adding that the six arrested activists, all residents of Haryana, told the police that they had been sent by Goyal.

The six activists tried to damage the Mohali ground but their attempt was foiled due to timely action by the PCA security personnel and the Punjab police.

The DIG said Goyal had been booked under section 120-B (criminal conspiracy) while others have been arrested under various sections of the IPC relating to trespassing, rioting, creating communal disharmony and criminal conspiracy.

Jain further said the six were armed with iron rods and sneaked in after jumping the wall and through internal gates and managed to reach the middle where they tried to cause some damage to two of the cricket pitches.

But they were caught by the PCA officials, who handed them over to the police, which reached immediately, he said.

SSP Singh said the six "came silently by bus and reached the stadium in an auto rickshaw. Once inside they raised slogans. No slogans were raised outside which could have alerted the mobile police deployed outside or the private security guards at the stadium."

Police said the incident appeared to have been carried out to gain publicity as the Shiv Sainiks claimed to have informed the national media in Delhi even before they reached the PCA stadium.

During interrogation, the six, who carried the identity cards of Shiv Sena, said that Goyal had held a meeting in Delhi on February 1 to chalk out the entire plan, the SSP said.

Asked if Bal Thackeray would also be booked in the case, Jain said, "Since we are determined to act against all those involved, it covers Thackeray, if his role comes in during the investigations of the case being done by the police."

"We are determined to ensure safety," he added.

Jain said the Punjab Police would ensure proper safety and security at the stadium for the match.

"The directions from the chief minister are clear that it a prestigious event and the administration is fully prepared to deal with vandalism," the DIG said, adding that security of the visitors from across the border would also be ensured.

The security measures would be implemented in coordination with the PCA, which has deployed private security guards. The DGP of Punjab is himself monitoring the security measures and other related issues, Jain said.

Jain, who later inter-acted with the media at a press conference, addressed by PCA president I S Bindra, said, "A comprehensive security plan had been worked out for the match," after holding discussions with the PCA officials.

He said a three-layer security measure would be in place with personnel immediately at the outer level, middle level and the water channel between the spectator's stands and the playing field.

The PCA has been asked to issue 'Photo Identity Cards' to all those authorised to enter the stadium and a Police Control Room would be functional round-the-clock, Jain said.

He identified the arrested activists as Jind Shiv Sena president Suresh Sharma, vice-president Rakesh Verma, Hissar unit president Shiv Kumar, Aman Khatkar, district organization minister, Jind, Pradeep Rana, district president Kaithal and Sandeep Sharma, a worker from Narwana.