The Iranian suspects in the Bangkok blasts were planning to attack Israeli diplomats, a senior Thai intelligence official said. Earlier blasts in India and Georgia also targeted Israelis this week.
Thai 'red shirt' protesters ruled out negotiations with the government Sunday, one day after clashes during the Thailand protests killed at least 21 people in the country's deadliest political violence since 1992.
The governments of Thailand and Britain have deemed the GT200 bomb detector unreliable, but the Thai military continues to use it to make arrests in the Muslim south.
The prime minister Friday extended the state of emergency he declared last week after rival protesters descended on the capital.
Activists have disrupted air and rail travel, and refuse to leave government grounds.