A time bomb ripped through a train in southern Pakistan just before dawn Sunday, killing 26 people and wounding 45 others, many of them seriously, police and emergency workers said.

The government accused India's intelligence service of responsibility, a charge India dismissed as "preposterous."The 18-carriage express was traveling through a village outside Sukkur, 120 miles north of Karachi, when the bomb exploded, police said. Among the dead were four children age 5 or younger.

"When we arrived, the carriage was destroyed and bodies were blown to pieces," said ambulance driver Mohammed Hafiz. "Many of the passengers were trapped and shouting for help."

Blaming India's Research and Analysis Wing for Sunday's bombing as well as previous attacks, Pakistan's Information Minister Mushahid Hussein said the neighboring country is trying to "destabilize Pakistan through acts of terrorism."

India and Pakistan routinely blame the other after apparent terrorist actions, but rarely provide evidence to support their claims. Both countries also have internal ethnic and religious conflicts that often lead to killings, bombings and riots.

It would be difficult to put Sunday's bombing in an ethnic context, however, since it did not seem to have a specific target and the explosive device was more powerful and more professionally assembled than is usually seen in local disturbances.