An image released by the Royal Thai Police on August 19, 2015, shows a sketch of the main suspect in Monday's deadly blast, in central Bangkok, Thailand, Aug 19, 2015.[Photo/Agencies]

BANGKOK - Thai police arrested a foreign suspect and seized bomb-making materials Saturday in the investigation of a deadly shrine bombing, officials said.

"It is most likely he is related to the bombing at Rajaprasong," deputy police chief Chakthip Chaijinda said of the suspect. The blast at the Erawan Shrine in the commercial Rajaprasong district of the capital on Aug. 17 killed 20 people, including foreigners.

The man was arrested Saturday in Nong Jok on the outskirts of Bangkok. Chakthip said, "We found bomb materials in his apartment."

National police spokesman Prawut Thawornsiri said that the arrested person is a foreigner, but refused to say if he was Turkish, as was reported by some local news organizations.

He said a news conference was planned later Saturday.

Soon after the bombing, police released an artist's sketch of a man seen in a security camera video from the open-air shrine leaving a backpack at a bench and walking away. A separate camera showed the suspect, wearing a yellow T-shirt, on the back of a motorcycle taxi leaving the site.

An arrest warrant issued earlier for the unknown suspect described him as a "foreign man," although a military spokesman said a connection to international terrorism seemed unlikely.