Central America developments

Since the beginning of 1982, the United States has increased the number of military advisers in Honduras from 14 last September to as many as 100, the largest attachment to any Central American country, the New York Times reports.

* Managua, Nicaragua - Nicaragua requested an urgent meeting of the United Nations Security Council to discuss what it called an ''imminent'' invasion organized by Washington. The US will not oppose such a meeting, says US Ambassador to the UN Jeane J. Kirkpatrick, in an apparent contradiction Secretary of State Alexander M. Haig Jr.'sstatement that the UN has no role to play in the Central American conflict.

* San Salvador - President Jose Napoleon Duarte has promised to investigate personally the killing of four Dutch newsmen in northern El Salvador, and invited journalists to accompany him.

Contradicting An army report, a doctor who performed autopsies on the men said he could not tell if they had been executed or killed in a cross-fire as the government maintains. Reporters who visited the scene of the slayings said they saw a tree trunk, bloodied and full of bullet holes, and that it appeAred victims had been placed against it and shot.

* Managua, Nicaragua - The leftist Nicaraguan government detained 19 Jehovah's Witnesses missionaries and expelled half of them for counterrevolutionary activity, a US Embassy spokesman said.

* Washington - The Reagan administration issued a new, unclassified ''white paper'' describing Cuban and Nicaraguan backing for the Salvadoran guerrillas. But the paper lacked the secret sourcing which had been provided earlier at a briefing for former top government officials. Lack of sourcing could weaken the White House case.

The report said last December Cuban President Fidel Castro ordered a step-up in arms shipments to the Salvadoran guerrillas for an offensive aimed at disrupting El Salvador's March 28 elections. It named three Nicaraguan ships alleged to have carried weapons from Cuba headed for El Salvador, and an airfield northwest of Managua as having been used for airlift of weapons from Nicaragua.

* Guatemala City - Thirty bodies, almost all with bullet wounds, have been found in various parts of Guatemala in the last 24 hours, police said. The bodies of 13 Indian peasants were discovered in a common grave near the town of Chimaltenango.

* Havana - Mexican Foreign Minister Jorge Castaneda arrived in Havana to brief Cuban leaders on his recent discussions with Secretary of State Alexander M. Haig Jr.

* Guatemala City - Leftist guerrillas shot and killed an Arkansas man at his plantation in northern Guatemala, the second American slain in less than two months, the US Embassy said. J. Pitts Jarvis was gunned down by men who called themselves members of the'Guerrilla Army of the Poor. A passing army helicopter spotted the rebels and opened fire on them, the spokesman said.