(KUNA) -- The Sri Lankan Air Force (SLAF) fighter jets Friday claimed to have destroyed a sea base of the Liberation Tigers of Tamil Eelam (LTTE) and 20 rebels have been killed in ground clashes with the government soldiers in the northern part of the island nation. "SLAF fighter jets attacked LTTE sea base at Allampili in the Mullaithivu area this morning," the Sri Lankan Defence Ministry said in a statement in Colombo. The target was destroyed in the attack, the Ministry claimed. In ground clashes, at least 13 LTTE cadres were killed today in North-western Mannar, the statement said, adding government troopers suffered no casualties. In another incident, three LTTE rebels were killed at Palaikulli in North-western Mannar region yesterday, news agency Press Trust of India reported tiday. In yet another incident at Parappakandal also in the Mannar region, as many as three rebels were killed yesterday, the Media Centre for National Security (MCNS) said today.In Navathkulam in Vavuniya, at least LTTE rebel was killed, the MCNS said. Meanwhile, Sri Lanka has said it could invite the LTTE for negotiations. "Once the government's devolution proposals are accepted by all democratic establishments in the country, they would have to be ratified by a referendum, " Sri Lankan newspaper 'Daily Mirror' reported Friday quoting Presidential advisor and parliamentarian Basil Rajapakse said. "After the proposals were ratified, the government would invite the LTTE for direct talks based on the proposals," said Basil Rajapakse, the younger brother of Sri Lankan President Mahinda Rajapakse. The President yesterday urged all political parties to end their differences and agree on a final draft on devolution package. Rajapakse said the government would give a new set of proposals to the LTTE based on the 'Mahinda Chintana', launched by the President for building a new Sri Lanka. Basil Rajapakse said the proposals would be drafted taking into consideration the sentiments of all stakeholders in the protracted ethnic conflict. The proposals would be preparted after the All Party Representative Committee (APRC) submits its report to President Rajapakse. The APRC is likely to submit its report by month-end, he added.