Twelve people were killed and other 100 injured when a female suicide bomber blew herself at the main railroad station in Colombo on Sunday, according to police. Most of the victims were students.

The government blamed the Tamil rebels for the attack, which was aimed at civilians in the crowded station.

Among those killed were five students and a coach from D.S. Senanayake College, a student from another private school from Sri Lanka’s capital, Holy Family Convent College, and a policeman, CNN reports.  

Authorities said that the accident occurred just when the train was pulling into Fort Station.

This incident came just hours after a grenade exploded at the Sri Lanka’s zoo on Sunday morning, leaving six people injured.

Police believes that the attack at the zoo was caused mainly to produce panic rather than casualties.

Violence in Sri Lanka has increased in recent months ever since the ceasefire agreement ended last month. Government vowed to take out the rebels in the first six months of 2008.

They are attacking the rebels’ territory almost daily. On the other hand, rebels are also launching offensive attacks using suicide bombers to attacks civilians.

The Liberation Tigers of Tamil Eelam, considered a terrorist group by the United States and European Union, has been blamed for over 240 suicide attacks.

On Saturday almost 18 people were killed when a bomb exploded on a bus, in the town of Dambulla, 90 miles, northeast of Colombo. Other 68 were injured and were hospitalized, the Associated Press informs.

These attacks come just as the country is preparing to celebrate on Monday 60 years of independence of Britain.

In recent days security in Colombo was tighten as troops searched civilians and cars before the ceremony which takes place Monday morning.