Former Sri Lankan president Mahinda Rajapaksa's brother Gotabhaya Rajapaksa launched his bid for the country's presidency Sunday, vowing to end "extremist terrorism" in the aftermath of the fatal Easter Sunday suicide attacks this April.

Gotabhaya, 70, was named as the candidate for Sri Lanka Podujana Peramuna (SLPP) party, known as Sri Lanka People's Front party in English, which was recently founded by the former president. Mahinda officially took over the party leadership on Sunday.

The Rajapaksas have been critical of Prime Minister Ranil Wickremesinghe's handling of the April bombings, which were blamed on a local Islamist militant group in the Buddhist-majority nation. At least 258 people were killed and nearly 500 wounded in the attacks that targeted three churches and three hotels.

Sri Lanka has been under a state of emergency ever since.

"I will not allow extremist terrorism under my presidency," Gotabhaya, who was the defense secretary during Mahinda's 2005-015 presidential term, said at the first national convention of SLPP in Colombo as he launched his campaign for elections, which are scheduled to be held between November and December this year.

Earlier at the event, chairman G L Peiris ceremoniously handed over the leadership of the party to Mahinda Rajapaksa, who in turn introduced his younger brother as the SLPP candidate for this year's presidential elections.

The former president described Gotabhaya as a leader "who could provide a new vision", Sri Lanka's English language daily The Island reported.

Addressing the gathering Gotabhaya said during his tenure as defense secretary, he has never allowed room for any foreign forces to interfere and he will do so in the future as well to protect the country's sovereignty.

"I have a vision for the future of my country. I never bowed my head to anyone who opposed my country. I will never allow anyone to infringe upon the sovereignty of Sri Lanka," he said

"Security is of foremost importance in a country. I assure you the safety of your children. I pledge to create a safe and secure environment in which all Sri Lankans, irrespective of their race or religion will be able to live in peace," he remarked.

It was during Gotabhaya's term as defense secretary that security forces crushed Tamil rebels and ended a 37-year separatist war in May 2009.

The no-holds-barred military campaign also triggered allegations of grave human rights abuses, including the killing of up to 40,000 Tamil civilians in the final months of fighting.

Gotabhaya is currently on bail facing prosecution for allegedly siphoning off millions of rupees of state cash to build a monument for his parents when his brother was president.

He also faces a civil suit in the United States for allegedly causing the death of a prominent anti-establishment newspaper editor in Sri Lanka in January 2009. The junior Rajapaksa is in the process of denouncing his U.S. citizenship.

The SLPP is a breakaway faction of the Sri Lanka Freedom Party (SLFP), which is nominally led by current President Maithripala Sirisena. Highlighting frequent schisms in the country's politics, the SLFP in turn broke away from a coalition with Wickremesinghe's right-wing United National Party (UNP) earlier this year.

Wickremesinghe has indicated he too wants to run for president, but his party is yet to nominate an official candidate amid major internal clashes over his leadership.

Incumbent Sirisena also plans to run again.

(With input from AFP)