Meanwhile, a pro-rebel website said troops were amassing heavy weapons along the de facto border in the island's north and there were long range attacks.
The renewed attacks came as peace broker Norway failed on Friday to secure an agreement to end a blockade on the Jaffna peninsula where nearly half a million people are trapped by fighting.
Five Tamil youth were killed and two injured in a grenade explosion in the eastern port city of Trincomalee Monday evening, causing tension in the area.
Sri Lankan troops and Tamil Tigers have further compounded the fragile ceasefire in the island nation by resorting to heavy artillery fire in the rebel fronts of Jaffna and Trincomalee, which claimed at least four lives.
The latest bombing raised to 37 the number of people killed in the past three days and raised fears for next week's scheduled talks between the government and Tamil Tiger rebels.
The Panama registered tanker New Diamond was carrying 270,000 metric tonnes of crude oil from Kuwait to India when its engine room caught fire off the coast of Sangamankanda in the eastern district of Ampara, Sri Lankan Navy spokesman Capt Indika Silva said.
The navy said that so far the 270,000 metric tonnes of crude oil it was carrying had not been affected by the fire.
Chances are any such disruption will not occur on the major shipping lanes but on some edge of the ocean between India and China. Even if there is no actual disruption, the costs of averting one can be punitive. The setting for this is provided by the energy shortage both countries face, says Subhomoy Bhattacharjee.
Centre ordered release of Rs 1,086 crore to four states as advance financial assistance for undertaking preventive and relief measures to deal with the cyclone.
The Sri Lankan Navy on Thursday arrested 32 Indian fishermen for alleged illegal fishing off the east coast, taking the total number of fishermen arrested during the last two days to nearly 70.
Building relations in the Indian Ocean, New Delhi has gifted naval vessels to Mauritius, the Maldives and Sri Lanka, even as China eyes the same locales.
As many as 86 Indian fishermen have been arrested and their 10 fishing boats seized by the Sri Lanka Navy for allegedly poaching in the country's waters, naval officials said on Friday.
Over 35 Chinese fishermen, detained by Sri Lanka for allegedly poaching in the country's waters were released on Monday within 24 hours of their arrest.
Area residents and environmental groups have resisted the coal power plant ever since it was originally proposed in 2006 due to worries about land clearance and pollution
The navy has so far held two exercises under code name 'SLINEX' and the last edition was held along the coast of Trincomalee in September, 2011 after the first in 2005.
'With Punjab and Kashmir in flames, it would not have been politically wise to alienate the West.' 'It would have inclined Western countries towards Pakistan.' 'It would have been a self-goal.'
The Sri Lankan Navy on Wednesday released 42 fishermen arrested by it for allegedly violating the International Maritime Boundary Line, a senior Fisheries Department official said.
Thirteen fishermen from Tamil Nadu have been arrested by the Sri Lankan Navy for allegedly poaching in Lankan territorial waters.
A "very severe" cyclonic storm lay centered about 250 km of Chennai, with the weather office forecasting winds touching up to 135 kph and advising fishermen against venturing into sea for the next two days.
Foreign Secretary Nirupama Rao will undertake a three-day visit to Sri Lanka from Monday. She is expected to visit the north eastern provinces of Sri Lanka -- including Vayunia, Yazhpanam and Trincomalee -- to check the rehabilitation of the Tamil population, who were displaced by the military's offensive against the Liberation Tigers of Tamil Eelam. Rao is also expected to prepare the ground work for the official visit of External Affairs Minister S M Krishna to Colombo.
Having spent months in refugee camps, the homecoming to northern Sri Lanka is turning bitter for nearly 1,500 war-displaced Tamil families, as their houses have been unlawfully occupied allegedly by Sinhalese people.
The International Organisation for Migration has helped about 90,000 displaced Tamils, lodged in the Menik Farm camps in Vavuniya, to return to their towns and villages in northern Sri Lanka.
A behind-the-scenes account of how the three-decade old conflict came to an end in the island nation.
'Rajapaksa's victory poses a serious foreign policy challenge for the Modi government,' notes Ambassador M K Bhadrakumar.
Two courts in Tamil Nadu have ordered the release of 61 Sri Lankan fishermen arrested between July and November last year.
Heavy falls at isolated places are very likely over Kerala on April 29 and 30. The system will not make landfall in Tamil Nadu, but may bring light rain in some northern parts, it said.
Colombo seems to be veering to the middle path between China and the US on global matters, but in regional matters of strategic security, it is increasingly identifying with India, points out N Sathiya Moorthy.
The fighting started after Naval personnel intercepted a group of Sea Tiger boats moving toward the Pulmodai area on the northeast coast.
Brigadier Prasad Samarasinghe, a military spokesman, said a suicide bomber rammed a truck filled with explosives into the naval convoy that was carrying sailors to the north-eastern port city of Trincomalee after they had finished their leave.
The fighting since last Wednesday at Muttur, which the military said was a diversion from the main battles near the Maavilaru min-dam, or anicut, has left some 30,000 refugees.
The victims were on their way to reinforce government troops battling Tamil Tiger rebels in the same area.
There was no immediate confirmation of the incident from the Liberation Tigers of Tamil Eelam.
The LTTE said at least 26 civilians were killed in attacks carried out by the military on Monday, but did not say if they suffered any losses.
Sixty-five Indian fishermen in nine trawlers have been detained by the Sri Lankan navy for allegedly violating the international maritime border.
The defence ministry said the students carried the grenade, which exploded accidentally and caused their deaths.\n
Five naval warships from Mumbai, Kochi and Vishakhapatnam have set sail for Trincomalee and Galle ports in Sri Lanka in response to an SOS from the Sri Lankan government.
Prime Minister Narendra Modi's ambitions abroad may run the risk of foundering on constraints at home.
US-India defence cooperation must not adversely affect the India-Russia interface, which has its own strategic meaning and content, asserts Vice Admiral Premvir Das (retd).
Public sector oil giant Indian Oil Corporation is investing $100 million in its Sri Lankan subsidiary Lanka IOC Ltd during 2004-05 as part of its retail foray in the island country.