YANGON, Myanmar — The aid agency Caritas Internationalis is at work in Myanmar, where the death toll could reach 500,000 after May 3’s pounding from Tropical Cyclone Nargis.

Caritas is coordinating relief efforts for its 162 national members and working with staff in the region. But a spokeswoman said communications to Myanmar have been severely affected and a clear picture of the devastation is yet to emerge.

The death toll could reach 100,000, as there are still thousands of people unaccounted for.

Dolores Halpin-Bachmann, emergency response team leader for Caritas Internationalis, said, “There is an urgent need for access to aid workers to the affected areas so that we can assess the damage, start to provide food, shelter, clean water and medical assistance. Myanmar is a poor country and will most likely need international help to respond to a disaster on this scale.”

“We’ve only been receiving sketchy reports, but they’re enough to make us concerned about the humanitarian situation,” she added. “Nagris hit a major city with a population of 5 million people. In that environment, we know how important it is for people to get access to clean water to stop the spread of disease.”

Halpin-Bachmann said, “Caritas knows from experience that the first few days are crucial to saving lives. Following the Asia Tsunami in 2004, hundreds of thousands of lives were saved because of the rapid and effective response of the humanitarian community in the early phase of the emergency. The government must do all it can to help aid workers respond.”

Elizabeth Griffin, communications director for the U.S. bishops’ Catholic Relief Services, said the Baltimore-based agency was ready to respond to those affected by the cyclone, but “we have not received an official request.”

Eleonore Fournier-Tombs, communications officer for the Canadian Catholic aid organization Development and Peace, said May 5 that it was evaluating the situation to create an appropriate action plan.

About 1% of the population of junta-ruled Myanmar is Catholic. A great majority of its citizens are Buddhist.

Pope Benedict XVI expressed deep sadness and “heartfelt sympathy” May 4 after hearing news of “the tragic aftermath” of the cyclone.

In a telegram sent on behalf of the Holy Father by the Vatican secretary of state, Cardinal Tarcisio Bertone, the Pope said he was praying for the victims and their families and called for “divine strength and comfort upon the homeless and all who are suffering.”

A copy of the telegram, addressed to Archbishop Paul Zinghtung Grawng of Mandalay, president of the Catholic Bishops’ Conference of Myanmar, was released by the Vatican May 6.

Benedict said he was “confident that the international community will respond with generous and effective relief to the needs” of those hit by the cyclone.

CNS contributed to this report.