Dhaka, Aug 26 - Bangladesh Prime Minister Sheikh Hasina has ordered two dredgers for two rivers, which feed the country's principal ports at Chittagong and Mongla, to keep them fully navigable.

It is part of a long-term plan to revive the country's 310 'dying' rivers, many of which have not been dredged since World War II.

Directing the authorities concerned Tuesday to immediately formulate a complete action plan for dredging the country's silted rivers, she said no single project should exceed 15 years.

Dredging should be done on a regular basis, she told the first meeting of a recently formed high-powered committee on river dredging and water resource management, United News of Bangladesh (UNB) news agency reported.

'Rivers must be given back their navigability immediately,' she told the officials.