Police in Bangkok Wednesday said a second arrest warrant has been issued in connection to a wave of deadly bomb attacks in Thailand.

Four people were killed and dozens injured after a series of explosions in seven provinces in Thailand’s south last Thursday and Friday.

No one has claimed responsibility for the attacks, but police have publicly ruled out links to foreign militants.

As long as there’s no link to terrorist groups, said the deputy police major, we’re still confirming it was local sabotage.

Police officials also visited some of the injured tourists in hospital.

Tourism accounts for 10 percent of Thailand’s GDP and officials say the country could lose hundreds of millions in revenue after the attacks.

Embassies in Thailand have warned their citizens to stay vigilant because there could be more attacks.

The explosions happened just days after the country voted in favor of a new military-backed constitution.