Sri Lankans on Thursday witnessed a fierce battle in the north and a Claymore mine attack in the capital Colombo in less than nine hours, a clear sign that the security situation is deteriorating further.

The Liberation Tigers of Tamil Eelam (LTTE) launched a land and sea attack against the Navy at the Delft island near the northern Jaffna peninsula early Thursday, killing at least four Navy sailors and injuring four others.

According to the military, about 18 Sea Tiger boats, including six suicide boats and 12 attack craft attempted to breach a Navy security point south of the Delft island around 00:30 a.m. local time (1900 GMT).

"The pre dawn LTTE Sea Tiger attack on the Delft Island was successfully repulsed by the Navy killing 18 Sea Tigers and destroying four LTTE boats," said a statement of the Media Center for National Security.

The Navy's Dovra Fast Attack Craft completely destroyed two LTTE Sea Tiger boats forcing the enemy flotilla to flee, and the Air Force engaged withdrawing Sea Tiger boats destroying two and disabling another, said the military.

However, the pro-LTTE website TamilNet quoted LTTE military spokesman Irasiah Ilanthirayan as saying that at least 30 Navy sailors were killed in the battle while four LTTE members died.

Ilanthirayan also said a Dvora Fast Attack Craft of the Navy was destroyed and two other Navy vessels sustained damages in the clash that lasted for two hours.

He said the LTTE cadres completed their "surprise mission" in two hours and returned to their base with weapons seized from the Navy.

Ilanthirayan's claim has been denied by the Navy, saying that no naval craft was destroyed or damaged in the attack.

The Navy said the search operation launched by naval troops in Delft following the attack concluded by noon on Thursday.

In the capital Colombo, one soldier was killed and six people including three civilians were injured in a Claymore mine attack carried out by suspected Tamil Tiger rebels at about 9:00 a.m. (0330 GMT).

An Army bus was caught by the explosion occurred near the heavily guarded Colombo Harbor.

The remote controlled Claymore bomb was tied to a motor bike parked by the roadside near the third gate at Colombo Harbor, said the Army.

Four soldiers inside the bus were injured in addition to three civilians who were also admitted to the hospital for injuries and shock. One soldier succumbed to his injuries in the hospital.

A few shop buildings at the location were damaged as a result of the impact of the explosion.

Most of the shops in the area closed after the explosion.

The two incident came after less than one month of an LTTE air raid against two oil facilities in Colombo.

Clashes between government troops and LTTE rebels are now an almost daily occurrence in the island country's north and east.

Claiming discrimination at the hands of the majority ethnic Sinhalese-dominated government, the LTTE has been fighting for an independent homeland for Sri Lanka's 12.5 percent Tamil minority since the 1970s.

Nearly 70,000 people have died in the conflict, including nearly 5,000 killed since December 2005, when violence escalated despite the Norwegian-arranged truce in place.

The LTTE has vowed never to return to talks unless the government halts its military campaign against them.

S. P. Thamilselvan, the leader of LTTE's political told the TamilNet on Saturday that attacks by government forces would not force them to compromise.

He said the government was trying to present the campaign as part of the "war on terror" to win international support.

"The LTTE and the Tamil people under no circumstances will come to the table in a position of political and military weakness," Thamilselvan said.

He also rejected a new offer of a political settlement from President Mahinda Rajapakse's Sri Lanka Freedom Party, saying it showed that "the Sinhalese leadership is still balking at proposing a just solution."

On the other hand, President Rajapakse has said that he would not leave the ethnic issue to the next generation.

Some government officials even claimed the security force will defeat the LTTE within three years.

With both the government and the LTTE refuse to comprise, there is little chance for the security situation to improve in the near future, analysts say.