COLOMBO, Jan. 12 (Xinhuanet) -- At least 9 Sri Lankan Navy troopers have been killed in an explosion in northern Sri Lanka, defense officials said Thursday.

    A bus carrying Navy personnel was hit by a claymore mine detonated by the Tamil Tigers at Chettikulam, Vavuniya, at 4.15 p.m. local time (1015 GMT), according to the officials.

    Seven more were said to be injured. The sailors were those returning on leave.

    This was the second attack on the Navy within five days as theTamil Tigers were blamed for an attack on a Navy fast attack craft early Sunday morning in which 13 sailors died.

    Thursday's explosion came after the government spokesman announced that the government would remain unprovoked by the Liberation Tigers of Tamil Eelam (LTTE) violence.

    About 60 soldiers have lost their lives in continued attacks through claymore mines since Dec. 1, 2005.

    The February 2002 cease-fire came into force after the deaths of more than 64,000 people over two decades of fierce armed engagements in this Indian ocean island. Enditem