Taiwan dispatched four coast guard and naval vessels Sunday to beef up patrols in waters near the Philippines after its authorities demanded an official apology by Wednesday for the death of a Taiwanese fisherman shot by Filipino coast guards.

"The government is determined to protect our fishermen," cabinet spokeswoman Cheng Li-wen said in a statement as a Lafayette-class naval frigate and coast guard vessels set sail for the area where the 65-year-old Taiwanese fisherman was killed Thursday.

The move came shortly after authorities issued a strongly-worded statement late Saturday night demanding Manila apologize to Taiwan and compensate the family of the dead man.

Taiwan also asked  Philippine authorities to bring the coast guards responsible to justice and start negotiating with Taipei on a proposed fishery agreement.

"If the Philippine government does not make a positive response within 72 hours, Taiwan will freeze all applications of Philippine laborers, recall its representative to the Philippines and ask the representative of the Philippines in Taipei to leave," the statement said.

Hung Shih-cheng, the skipper of the 15-ton Kuang Ta Hsin No. 28, was killed during the incident on Thursday morning, which also left the boat riddled with more than 50 bullet holes.

The Chinese mainland also expressed grave concern over the incident and strongly condemned the fatal shooting, calling the action "barbaric."

The incident immediately angered people from both Taiwan and the Chinese mainland after Armand Balilo, Philippine coast guard spokesman, said the incident "deserves our sympathy but not an apology."

Several Taiwan newspapers, including the Taipei-based China Times and the Apple Daily, called the shooting a criminal case and demanded a strong response from the Taiwan authorities.

Hackers from Taiwan attacked and temporarily paralyzed several Philippine government websites Friday night, reported the Apple Daily.

Internet users and some observers from the Chinese mainland, on the other hand, have called for Beijing to take strong action in assisting Taiwan's ultimatum.

"China has reiterated over time that Taiwan is an integral part of China. Now is a good opportunity to show that China will not tolerate the shooting of our fishermen, whether they are from the mainland or Taiwan, and that our government is determined to protect the life of its people, as is stated in the national defense white paper," said Zhuang Guotu, dean of the Research School of Southeast Asian Studies at Xiamen University on Sunday.

"It's not only for the Philippines. It sends out a warning and prevents similar killings from happening in the future from countries that claim to have territorial disputes with China," added Zhuang.

Others have called for collaboration between the Chinese mainland and Taiwan on sovereignty in the South China Sea.

Li Jiaquan, a scholar with the Taiwan Research Institute of the Chinese Academy of Social Sciences, told the Beijing Times that as tensions grew after the shooting, Taiwan may consider for the first time working with the mainland to fend off the Philippines.

But many have slammed this cooperation as counterproductive.

"Such cooperation, especially in military and politics, may attract unwanted attention from the US and Japan, who see such collaboration as a threatening signal of a power transition in the Asia-Pacific," Chen I-hsin, a political science professor from Tamkong University, told the Global Times.

Li Fei, a professor with the Taiwan Research Institute at Xiamen University, echoed Chen's opinion.

Li told the Global Times that the Chinese mainland should "act more and talk less" by sending more patrol ships to the area and avoiding using rhetoric that might put pressure on Taiwan authorities.

No response had been heard from the Philippines government regarding Taiwan's ultimatum as of Sunday night.

Abigail Valte, a spokeswoman for Philippine President Benigno Aquino, told a government radio station that the authorities had launched a "transparent and impartial investigation" into the incident but decline to respond "as of the moment," the Taiwan-based Central News Agency reported on Sunday.

Analysts said the response could be delayed by the mid-term polls which take place on Monday amid escalated conflict and violence.

"The Philippine government has weak control over the military. There is the possibility that the shooting serves to 'stir the water' for the coming election," Zhuang told the Global Times.

Agencies contributed to the story