TAIPEI - Taiwan authorities raided the offices of two firms linked to massive gas explosions that killed 28 people as the island flew flags at half-mast Tuesday to mourn the blast victims and 48 killed in an earlier plane crash.
Prosecutors overnight searched the offices of LCY Chemical Corp, a company allegedly responsible for the deadly explosions last Thursday that also injured more than 300 in the island's second largest city Kaohsiung.
They also raided China General Terminal Distribution Corp, a chemical distributor contracted by LCY Chemical to deliver propene from a pier to a chemical plant 20 kilometres away through an LCY Chemical-owned pipeline system beneath the city.
Prosecutors took away documents from the two firms that recorded the shipment of propene which prosecutor Huang Yuan-kuan said "should be useful in helping clarify the case".
The Kaohsiung city government says evidence shows that around 10 tonnes of propene might have leaked in the hours before the first explosion and blames LCY Chemical for the deadly blasts which tore up city streets.
President Ma Ying-jeou has vowed a full investigation into the cause of the incident and a review of the pipe network.
Kaohsiung lies adjacent to a huge petrochemical complex housing dozens of plants and many pipelines run under the densely packed city.
The explosions were the second disaster to strike Taiwan in just over a week, after a TransAsia Airways plane crashed with the loss of 48 people on July 23.
Government spokesman Sun Lih-chyun told AFP the Taiwanese flag would be flown at half-mast from public buildings for three days of national mourning for "our compatriots who died unfortunately in the two accidents".