There's no need to pressure me. If we have clear information, I'll tell you. If it's still sketchy, I can't say anything. This is a complicated matter, and at this stage we won't implicate anyone," he said.
National police chief Chakthip Chaichinda said Monday that police are still considering all possibilities while focusing on a politically-driven motive.
"We're covering all the bases but the referendum issue is our focus. But I can assure you it has nothing to do with the Erawan shrine bombing last August," he said.
Asked about similarities between the explosive devices used in the deep South and those in the seven provinces, the police chief said making connections is more important and the police are working to establish whether there is one.