A tropical storm sliding north along Central America today has unleashed heavy rains that have killed at least two people in Costa Rica, with forecasters predicting it could strengthen into a hurricane headed for the United States.

Costa Rica declared a national emergency as it struggled with mudslides, washed out roads and overflowing rivers.

Schools, universities, government offices and state banks across the Central American nation were closed.

“We have confirmation that at least two people have died and several who are missing are being sought by emergency teams,” Costa Rican President Luis Guillermo Solis told reporters.

The two fatalities were Nicaraguan farm workers on a property in the central east of the country. More than 5,000 people were being put up in shelters after having to abandon their homes because of flooding and the risk of mudslides, the director of the National Emergency Commission, Ivan Brenes, said.

The rain was caused by Tropical Storm Nate, which on Thursday was located overland in eastern Nicaragua.

The US National Hurricane Centre said it expected the storm to keep tracking north, gaining force as it went.

It said Tropical Storm Nate would be “near hurricane intensity” by the time it hit Mexico’s southern Yucatan Peninsula late Friday, then strengthen into a hurricane as it crossed the Gulf of Mexico to hit the southern United States somewhere between the states of Louisiana and Florida.

“It is too early to specify the exact timing, location, or magnitude of these impacts,” the centre said.

The United States is recovering up from two major hurricanes: Hurricane Harvey that tore through Texas in August and Hurricane Irma in September.

Another powerful storm, Hurricane Maria, ripped across Caribbean islands in late September, wreaking destruction in several countries and territories, including Dominica and Puerto Rico. In Costa Rica, an alert was issued for people to be wary of crocodiles that might be roaming after rivers and estuaries flooded.

Concerned football officials were monitoring the situation but said they intended to go ahead with a World Cup qualifying match between Costa Rica and Honduras scheduled for late Friday in the capital San Jose.

The annual rainy season is currently underway in Central America, a five-month period typically ending in November in which the risk of flooding and mudslides rise.

This year’s has been intense, with some areas in the region getting up to 50 per cent more rain than average for September and October.

The worst-hit country in the region has been Honduras, where 32 people have died so far this season, according to national emergency service officials.

Guatemala suffered 26 deaths, and another 300,000 people were affected, and 4,000 homes were damaged.

In El Salvador, six people died and a national alert urging vigilance was issued last week. In Panama, a mudslide on Saturday killed six people in an indigenous area.

Belize issued a public warning over Tropical Storm Nate, urging “preparations to protect life and property” and for people in flood-prone areas to move to higher ground.