The Maruti 800 car used by the suspected militants had a fake registration number, and its chassis and engine numbers were also tampered with, the police said.

While the registration number (UP14E9531) was found to be that of a Bajaj Chetak scooter, registered in the name of one Pawan Verma in Ghaziabad, the chassis and engine numbers were illegible, the police said.

Ghaziabad police first picked up Verma from Shahpur-Bamheta village near Lal Kuan for questioning — three others who had bought the scooter from him in turn were also picked up.

Verma told the police that he had sold the scooter some years ago to an acquaintance, a resident of Dadri named Anuj Sharma. According to the police, Sharma in turn said he had sold it to a friend Krishna, who said he sold it a few months after buying to a fruit-seller in Dadri.

A police team then picked up the fruit-seller, Monu, who works in the Dadri fruit mandi.

“The trail led to these people one after the other. We had to bring all of them to the police station for questioning,” a Ghaziabad police officer said.

All four were in custody at Kavi Nagar police station and were being questioned when reports last came in on Sunday evening.