Thai police say they will push for the suspected mastermind behind an alleged bomb plot discovered in Bangkok on Valentine's Day to be extradited from Iran.

Police Gen Pansiri Prapawat says Norouzi Shayan Ali Akbar was the “key player” who planned the botched attack in Thailand's capital along with four other Iranians.

Pansiri said Tuesday that police will also ask the Thai government to request the extradition from Iran of Leila Rohani, who is believed to have helped accommodate the suspects prior to the explosions.

Police Lt Gen Winai Thongsong said investigators have so far found no links between the suspects and any international terrorist organisations.

Thai police said earlier that the group was targeting Israeli diplomats. - Sapa-AP