HANOI, Vietnam (AP) — Some villages in Vietnam are still isolated by landslides and destroyed bridges after a tropical depression last week that has become one of the country's worst natural disasters in years.

The Vietnam Disaster Management Authority said in a statement Monday the death toll has risen to 72 with 30 people still missing. The depression hit the central coast last Tuesday and damaged infrastructure and crops mainly in the central and northern regions. The disasters also injured 33 people, it added.

Disaster official Nguyen Thi Lien in northern Yen Bai province, where 15 people have died, said some 4,000 soldiers, policemen, militiamen and villagers were mobilized to search for 13 people still missing.

Meanwhile, Tropical Storm Khanun is expected to weaken to a tropical depression in the Tonkin Gulf later Monday and heavy rains are forecast in northeastern Vietnam.

Vietnam is ranked the seventh most disaster-prone country in the world, and disasters over the past two decades have caused more than 13,000 deaths and property damage in excess of $6.4 billion, according to Achim Fock, acting country director for the World Bank in Vietnam.