Hinting that Maharashtra Navnirman Ssena chief Raj Thackeray, who had fired a fresh salvo against north Indians on Saturday, may escape action, the Mumbai police on Monday said it was "difficult to find an explicit threat or provocation" in the text of his speech.

"He (Raj) was very careful this time and it seems he has consulted some legal experts before making the speech. For taking action, the offence needs to have been complete. And it is difficult to find an explicit threat or provocation in the speech text," a senior police officer said amidst widespread demand for action against MNS chief.

In the speech delivered at Shivaji Park in Mumbai, Raj describes the events leading to his arrest in February chronologically and then asks the audience if the action against him was right or wrong.

"We have to make sure that the case stands in court. During the speech, Raj has also made an emotional appeal to the ward officers and ration card officers uttering the words 'with folded hands' for not giving licenses for petty gains. This can be used as a defence (by him)," the officer said.

As regards use of foul language, it attracts action under various sections of the Indian Penal Code but is a non-cognisable offence, Mumbai Police Commissioner Hasan Gafoor told reporters.

Raj led an anti-north Indian campaign in February during which he was arrested on charges of inciting people.

The police have referred the entire speech text for scrutiny by a legal team and its reply is expected shortly, Gafoor said.

"This is very relative. A thing which is provocative for you cannot be so for me and therefore we need to study the entire speech. We have referred the matter to a team consisting of chief public prosecutor and a government pleader. If required, we will also seek the opinion of the Advocate General of Maharashtra Ravi Kadam," Gafoor added.

No instances of violence have been reported since Saturday evening, Gafoor said, making clear that this aspect will not influence the legal team's opinion.