A Turkish man was arrested on Saturday in northern Bangkok and is believed to be the main suspect behind the deadly shrine bombing in the Thai capital that killed 20 people, a media report said.

The arrest took place at Poon-Anand Apartment in Nongchok district of eastern Bangkok. A large quantity of explosive-making materials were found at the apartment, The Nation online reported.

The arrest was made after about 100 police and troops surrounded the apartment block for over two hours.

Among the things found were a 0.5 cm ball bearing similar to those found at the bomb sites at Ratchaprasong intersection and Sathorn pier.

The suspect was renting rooms No 412 and 414 on the fourth floor of the apartment, a police source said.

The explosion at the Erawan Shrine on August 17 killed 20 people, mostly foreign tourists and injured over 100 others.

A man in yellow shirt was seen leaving a backpack under bench in the shrine compound shortly before the bomb went off.

Feeds from security cameras led to facial sketch of a foreigner who appeared like an Arab.