Thai identification portrait of a 26-year-old female suspect is shown in this Thai Royal Police handout released yesterday. Police probing Thailand’s deadliest bombing issued arrest warrants yesterday for two suspects after a raid on a suburban apartment block uncovered possible bomb-making materials. Photo: Reuters

Police probing Thailand’s deadliest bombing issued arrest warrants yesterday for two suspects after a second weekend raid on a suburban apartment block uncovered possible bomb-making materials.

Police were looking for a 26-year-old Thai woman and a foreign man in his 40s after expanding their search to a property in the city’s Min Buri district. They found fertiliser, digital watches and an explosives detonator.

That came after a raid on an a decaying apartment building in the nearby Nong Chok district on Saturday, when police arrested a foreigner and seized several kinds of explosives and more than 200 passports.

The August 17 attack on a Bangkok Hindu shrine killed 20 people and injured more than 100. Fourteen foreigners were among those killed in a blast the military government said was aimed at dealing a blow to an already ailing economy for which tourism has become crucial.

A sketch of the man showed him with cropped hair and a short moustache. A picture of the female suspect, Wanna Suansant, showed her wearing a hijab. She rented the room occupied by the foreign man, for whom police issued the second arrest warrant, spokesman Prawut Thavornsiri said.

Police visited the family of the woman in southern Phangna province soon after the warrant was issued and were told she was living overseas.

“They said Wanna lives in Turkey with her Turkish partner and her child. She has not contacted them for a while,” deputy provincial police chief Taracha Thompat told Reuters by phone.

Police have been looking into a possible Turkish connection in their probe and last week said they were checking arrivals from that country.

Woman lives in Turkey with her Turkish partner and her child – she has not contacted them for a while

Fake Turkish passports were seized and police requested a Turkish translator to assist in questioning the suspect arrested on Saturday.

Prime Minister Prayuth Chan-ocha indicated at least one of the two suspects had been caught on closed-circuit cameras on the day of the bombing. However, he did not specify the location covered by the surveillance video.

Police have been criticised for an erratic investigation that had, until this weekend, uncovered few clues about who was behind the blast. No group has claimed responsibility.

Police have not confirmed the identity or nationality of the 28-year-old man they arrested on Saturday in the busy Nong Chok, area, where many Thai Muslims and foreigners live.