KUALA LUMPUR: A Pakistani and two Malaysians have been detained in connection with last month's bombing of a shrine in Bangkok that killed 20 people, the national police chief said Monday.

Inspector General Khalid Abu Bakar told reporters that the three were detained a few days ago following a tip-off by Thai authorities. He said one of the Malaysians is a woman.

The August 17 blast at the Erawan Shrine in the Thai capital killed 20 people, including five Malaysians from one family, and injured more than 120.

Many of the victims were foreigners as the shrine is a popular destination for tourists and Thais alike.

Read: Bomb explodes at Bangkok shrine, killing at least 18

Khalid did not give details or say where in Malaysia the three were detained, when they will be formally charged, or what the charges would be.

He said Malaysian police will investigate and work with Thai authorities on the detainees.

Also read: Thai police seek ‘Chinese’ man over Bangkok bomb

Thai police say the man who may have actually planted the bomb may have fled across Thailand's southern border to Malaysia, but Khalid refused to speculate on that.

In Bangkok, Thai Police Chief Somyot Poompanmoung said he has not received any information from the Malaysian police on the arrest of the three suspects.

Two key suspects are also in custody in Thailand, charged with possession of illegal explosives.

One of them was captured from an apartment on the outskirts of Bangkok where police also discovered bomb-making material. The other was caught near the border between Thailand and Cambodia, and police said his fingerprints were found on a container with explosive material confiscated from the apartment.

Also read: Turkish man charged over Bangkok bombing

After weeks of demurring, Thailand has suggested that those behind the blast may have been from a gang involved in smuggling Uighurs from the Chinese region of Xinjiang, while others speculate they may be separatists or Islamist extremists angry that Thailand repatriated more than 100 Uighurs to China in July.

Uighurs complain of oppression by the Chinese government, and some advocate turning Xinjiang into a separate Uighur state.

Thai police say the mastermind of the plot is a 27-year-old ethnic Uighur from China. They said they think the man may have fled to China.

Also read: Bangkok bomb plotter "flew to China", Malaysia lead goes nowhere