Deputy Metropolitan Police Chief Pansiri Prapawat, who is heading the investigation, did not give details of the suspects but said his team was looking into their possible links to the five Iranians already in custody.
Meanwhile, Iranian national Madani Mehrded, who was detained on Sunday, has been sentenced to three months in jail and fined 3000 baht for overstaying his visa. Mehrded will be interrogated by police who are looking into the February 14 bomb explosions.
The police expect to complete their probe into the blasts this week, after gathering evidence and details from interviews with witnesses, while waiting to question Masoud Seda Ghatzadeh.
The Iranian man is in Malaysian police custody pending likely extradition to Thailand.
The police found that the stickers imprinted with "SEJEAL" had been posted on Bangkok streets before the day of the blasts. Special Branch police has tried to decipher the meaning of the mysterious Arabic word.
Saeib Morabi, the Iranian suspect who lost both legs in his alleged two grenade attacks that backfired, would not be informed of the criminal charges against him until he recovers enough, the Nation newspaper said.
Pansiri thanked witnesses for their cooperation and the general public for helping, along with public prosecutors and the foreign ministry, which resulted in the police investigation "making good progress in two weeks' time".
He said he had assigned two more senior investigators to find out who were the intended targets. He declined to comment on a report that Iranian embassy officials recently visited the suspects and later said Iran was being smeared.
The police are maintaining tight security at the Israeli embassy located in an office tower in central Bangkok and at areas frequented by visitors from Israel and the Middle East.
