BURI RAM: A pregnant woman was stabbed to death by a monk she was allegedly trying to blackmail after having an affair with him, police said.

Police said the fatal stabbing occurred on a road in tambon Tum Yai on Monday afternoon.

Eyewitnesses told investigators that Phra Um Deeruenrom, 59, the abbot of Wat Ban Nong Bua, was driving a van and he intentionally drove into a pickup travelling towards him. 

The pickup was driven by a man who was with his wife, Lampai, 36, who was eight months pregnant.

The two vehicles were badly damaged.

The woman then got out of the pickup and ran away. The monk chased her, then stabbed her with a knife. She had two deep wounds to her head and another to her right wrist, and died at the scene.

Her baby also died.

The monk was later arrested. Police said he admitted to the crime, but refused to reveal the motive. 

However, villagers told police he had an affair with Lampai, who had called him many times, demanding money and blackmailing him.

The monk was expelled from the temple and then charged with murder.