Sri Lanka's main parties on Monday challenged in the highest court the president's sacking of parliament, a move which has escalated a political crisis and deepened international alarm.

Sri Lanka plunged deeper into crisis Saturday after President Maithripala Sirisena sacked parliament and called a snap election, leaving the country facing a further two months of damaging political paralysis.

Hundreds of Sri Lankans have been left homeless after explosions at an ammunition depot on the edge of Colombo flattened houses and killed a soldier, an official said Tuesday.

Thousands of residents are yet to return to their homes after a huge fire on Sunday night at the military store triggered the blasts and forced them to flee.

Sri Lanka appealed on Wednesday for foreign aid to recover from massive floods that caused an estimated $2 billion worth of damage and claimed more than 100 lives.

Finance Minister Ravi Karunanayake said 35,000 homes were damaged in last week's floods triggered by the heaviest rain for early 25 years, with the capital Colombo the hardest hit.

Floods subsided across Sri Lanka Tuesday revealing the full extent of damage from last week's deluge that also triggered landslides, officials said, as the death toll crossed 100.

The Disaster Management Center (DMC) said 101 people were known to have died last week while another 100 people were still listed as missing in the worst hit central district of Kegalle.

Foreign aid began arriving in Sri Lanka Saturday, bringing help to half a million people forced out of their homes by heavy rains and landslides that have killed at least 71 in a week of extreme weather wreaking havoc in South Asia.

As the heaviest rains in a quarter of a century battered Sri Lanka, Cyclone Roanu barreled into the Bangladesh coastline leaving six people dead and forcing the evacuation of 500,000 as it unleashed winds as strong as 88 kilometers (54 miles) per hour and heavy downpours.

Emergency workers in Sri Lanka on Tuesday found the bodies of a woman and two children killed in a landslide, taking the toll from two days of heavy rain to 11, with thousands more forced to flee their homes.

Another five people are missing across the island, parts of which have been underwater since Sunday, a spokesman for the Disaster Management Centre said.

Sri Lanka's police Sunday re-introduced war-time road blocks and random checks on vehicles following a surge in gang-related shootings in the capital, a spokesman said.

More than 100 police stations in Colombo and its suburbs have been asked to erect snap blocks, a common practice during the island's separatist war that ended nearly seven years ago, police spokesman Ruwan Gunasekera said.

Sri Lanka's government Thursday announced it would ban landmines and promised to destroy its stockpiles of the explosive devices, nearly seven years after its protracted civil war ended.

Deputy Foreign Minister Harsha de Silva said the cabinet had decided to sign the 1997 U.N. treaty which banned anti-personnel mines.

Sri Lanka must "confront and defeat the demons of its past", the U.N. human rights chief said Tuesday at the end of a visit to assess the island's progress in investigating war crimes.

Zeid Ra'ad Al Hussein said Sri Lanka had come a long way since this time last year, when former president Mahinda Rajapakse was ousted after a decade in power.