BANGKOK, Thailand — Thailand will install more surveillance cameras and better lighting in major tourist areas after two British tourists were killed last week on a resort island, a senior government official said Thursday.

More police and soldiers were being sent to help investigate the slayings of Hannah Witheridge, 23, and David Miller, 24, who were found battered to death on a Koh Tao beach last week.

Deputy Prime Minister Gen. Prawit Wongsuwan told reporters he has ordered the Interior Ministry, Bangkok’s city government and police to install the surveillance cameras and improve lighting. He said authorities are urgently investigating the case, which critics say has been bungled by police.

“The area where the incident happened was very dark. The closed-circuit cameras could not capture images. I have ordered (authorities) nationwide that there must be sufficient lighting, especially in Bangkok and major tourist cities. And there must be closed-circuit TV cameras all over the country,” Prawit said. “I’m confident we will see clearer results within two months.”

None of the dozens of DNA samples taken from migrant workers, Thai men and foreigners has matched the crime scene evidence, and no arrests have been made since the bodies were found on Sept. 15.

“Right now we have limited the investigation to some areas and some individuals. We are not getting lost like they said because we have to work systematically,” said Prawit.

The quiet, small island of Koh Tao is about 410 kilometres (250 miles) south of Bangkok. It’s a short boat ride from better-known Koh Samui and Koh Phangan, the latter known for raucous “full moon” parties that attract young travellers from Thailand and abroad.