Delhi Chief Minister Arvind Kejriwal was slapped by a man during a roadshow in Moti Nagar in the New Delhi constituency, prompting a strong reaction from the AAP which alleged the BJP was behind the "cowardly act".

Police said the man has been taken into the custody and an investigation into the matter is underway.

Kejriwal was on an open jeep when a man wearing a red t-shirt jumped onto the vehicle and slapped the chief minister before he was pulled off the jeep.

DCP (West) Monika Bhardwaj said the man has been identified as Suresh, 33, and he deals in spare parts in Kailash Park area.

Delhi Deputy Chief Minister Manish Sisodia slammed the BJP after the incident.

"Do Modi and Amit Shah want Kejriwal to be murdered?" Sisodia tweeted, attacking the prime minister and the BJP chief.

He said the BJP could not break the morale of Kejriwal and could not defeat him in elections in five years despite putting in all its might. "Now you want him removed form your way like this. You cowards! This Kejriwal is your end," he said in a tweet in Hindi.

AAP spokesperson Saurabh Bharadwaj too alleged that the BJP might be behind the attack and asserted the incident would not deter the spirit of the party.

"Delhi CM Arvind Kejriwal got attacked during the roadshow. We condemned this cowardly act. This opposition sponsored attack cannot stop the Aam Aadmi Party in Delhi," he said.

BJP Delhi president Manoj Tiwari condemned the incident and said the AAP might have "scripted" the incident.

"We do not support violence and condemn such action by anyone. But I have doubt as to why such incidents happen with Kejriwal in election time only.

"I doubt this incident may have been scripted by Kejriwal himself," Tiwari alleged.

Kejriwal was holding the roadshow in favour of New Delhi candidate Brijesh Goyal who is contesting from the Lok Sabha seat.

This is the second time Kejriwal has been slapped in a public rally. Earlier, he was also attacked with ink and spices.