The states of Quintana Roo and Yucatan are on a heightened state of alert as Tropical Storm Ernesto churns toward the Yucatan Peninsula, the Mexican national emergency management office said Tuesday.

A hurricane warning is in effect from Chetumal to Punta Allen on the east coast of the Yucatan Peninsula.

Areas in the southern and eastern sections of Campeche state are on a lower alert level, the Mexican national emergency management office said.

Chiapas, Tabasco and Veracruz states, as well as the rest of Campeche, are on the lowest level of alert since the storm will likely bring "moderate to strong rains to maritime, coastal and inland areas" in the Yucatan Peninsula, the emergency management office said.

The storm was 285 kilometers (177 miles) from Roatan Island, Honduras, and 420 kilometers (260 miles) east-southeast of Chetumal, the capital of Quintana Roo, at 7:30 a.m. (1230 GMT), the Mexican weather service said.

The storm is moving at 20 kph (12 mph) toward the west-northwest and is packing winds of 100 kph (62 mph), with gusts of 120 kph (75 mph), the Mexican weather service said.

Ernesto is expected intensify on Tuesday and become a Category 1 hurricane, forecasters said.

Ernesto is the fifth tropical cyclone of the 2012 Atlantic season, following Alberto, Beryl, Chris and Debby, which killed three people in the United States.

The season officially began on June 1 and ends on Nov. 30, but two storms - Alberto and Beryl - formed in May. EFE