TAIPEI (AFP) - Two men suspected of planting suitcases loaded with petrol on a high-speed train in Taiwan are expected to be extradited from China on Tuesday, police said.

The Taiwanese pair were arrested in the south-eastern Chinese city of Zhuhai and are scheduled to be sent back to Taiwan this afternoon, said an official at the Criminal Investigation Bureau.

The incident happened on Friday when two unattended suitcases were found on board a train bound for the capital Taipei, prompting the evacuation of more than 600 passengers.

Two other suitcases, also containing petrol, were found in lawmaker Lu Chia-chen's office in New Taipei city on Friday. Police were treating the two incidents as connected.

The bureau is scheduled to hold a press conference later on Tuesday on the two cases.

After discovering the two suitcases on the train, rail operator Taiwan High Speed Rail Corp evacuated passengers at Taoyuan station near Taipei and police removed the bags for investigation.

Officers searched the train for evidence and the platform for Taipei-bound trains was temporarily closed, the company said.

It said it had not received any threats prior to the incident.