Taiwan stepped up pressure on Manila Tuesday, saying it would conduct a naval drill in waters near the Philippines if Manila did not officially apologise for the killing of a Taiwanese fisherman. Taiwan has demanded the Philippines apologise by midnight Tuesday (1600 GMT) over the killing of the 65-year-old fisherman by coastguards last week or face a potential freeze in sending workers to the island. The defence ministry said the military was prepared to conduct an exercise in the waters where Hung Shih-cheng of the 15-tonne Guang Ta Hsin 28 was shot Thursday. Taiwan has also asked the Philippines to bring to justice the coastguards responsible and start negotiating a fisheries agreement. The state Central News Agency said the exercise would be held Thursday and involved a Kidd-class destroyer, a Perry-class frigate and three coastguard frigates. A number of fighter jets would also be involved in the drill which would for the first time target the Philippines as the enemy, it said. The incident has sparked public outrage in Taiwan, where hundreds of angry fishermen burned Philippine flags and hurled eggs at Manila's de facto embassy in Taipei Monday. Taiwan at the weekend sent four coastguard and naval vessels to protect its fishermen in waters near the Philippines. US State Department spokeswoman Jen Psaki has urged all sides "to refrain from provocative actions" while Philippine President Benigno Aquino called for calm and guaranteed an in-depth investigation into the incident. The Philippine coastguard has admitted firing at one of four Taiwanese fishing vessels it said had strayed into its waters, allegations denied by the victim's son who was with his father and two other sailors on the boat at the time. Taiwan prosecutor Liu Chia-kai described the incident as "nothing but a slaughter", after examining the boat which he said was hit by more than 50 bullets.