The president of Honduras has declared an immediate curfew in a town where 13 people were shot dead on Saturday.

Xiomara Castro described the killings in a pool hall in Choloma as a "brutal and ruthless terrorist attack".

The victims, who were at a birthday party, were 12 men and one woman.

Separate murders in the northern Sula Valley region brought Saturday's death toll to at least 20, authorities said, and are thought to be linked to drug-trafficking gangs.

The curfew comes in from 21:00 local time (04:00 BST) to 04:00 from Sunday and will run for at least 15 days.

It will be extended to nearby San Pedro Sula - the central American country's second-largest city - on 4 July.

Ms Castro said the measures were being put in place in response to "the brutal and ruthless terrorist attack by hired killers trained and directed by drug lords" in the Sula Valley.

"Multiple operations, raids, captures and checkpoints are initiated," she said.

The Honduran government has also said 1,000 additional security officers will be sent to the area and is offering a reward of around $33,000 (£26,000) for help identifying and capturing those responsible for the Choloma shootings.

A partial state of emergency in areas of the country has been in place since December as part of efforts to confront violent gangs, with the country struggling to bring escalating warfare and drug crime under control in recent years.

Along with neighbours El Salvador and Guatemala, the country is a major transit route for cocaine coming from South America to the United States.

The shooting came a week after at least 46 women were killed in gang violence as part of a prison riot near the capital Tegucigalpa.

Survivors told local media that it was triggered by rivalries between two of Central America's most notorious criminal organisations: the 18th Street Gang and MS-13.