He said police had video footage from security cameras at the intersection clearly showing the identity of the unnamed man that was linked to the bombing.

But he added, "If the image is not clear enough, police will not submit a request for the warrant."

Asked to comment on an earlier statement by Sunai Manomai-udom, director-general of the Justice Ministry's Department of Special Investigation (DSI), that the DSI had not yet had sufficient evidence against anyone, Seripisut angrily replied, "How can the DSI chief say so without seeing the police evidence?"

Deputy police chief Lt-General Jongrak Juthanont, head investigator handling the police probe into all nine bombs, said the four conditions under a police-DSI agreement should be reduced to two. Those are exchanging useful information about the bombings and swapping copies of official reports that each department submits to the Cabinet or the Council for National Security.

He said Seripisut had decided the two other conditions - joint acknowledgement by DSI agents on police acts that may hamper or violate human rights and the joint presence of DSI agents during police interrogation of suspects in custody - should be dropped, because the police have now taken over the case completely from DSI.

Jongrak said police investigators would seek a warrant at the Criminal Court today. "I am confident the footage is sufficient evidence to prompt the court to issue the warrant," he added.

Sunai later said the DSI still needed to run a parallel probe into the bombings, on orders from Premier Surayud Chulanont.