44 From U.S. and Canada Now Held- Officials of Nickel Plant Latest

Special to The New York Times

 HAVANA, June 30 - Two more Americans were kidnaped today by Cuban rebels, bringing to forty-four the number of North American servicemen and civilians seized since last Thursday.
 Those kidnaped today are officers of the Nicaro nickel plant on the North coast of  Oriente Province.
 Oriente is the center of operations of the rebels, led by Fidel Castro and his brother Raul, against the Government of President Fulgencio Batista. The rebels say they have carried out kidnaping to bring pressure on the United States Government to halt military aid and assistance to the Batista regime.
 Among the United States citizens seized- three of the victims are Canadians- are twenty-eight sailors and marines from the United States Naval Base at Guantanamo Bay, on the south coast of Oriente.
 
 U.S. Denies Rebel Charge
 
 Replying to a rebel charge that the base had been used by Cuban military planes operating against the insurgents, the United States Ambassador, Earl E. T. Smith, issued a statement yesterday saying that the base was not open to planes on combat operations.
 The rebels told a sailor whom they did not abduct that his kidnaped colleagues would be released today.
 United States officials have been in contact with the rebels in an attempt to negotiate the release of the naval and marine personnel as well as the ten Americans and two Canadians seized last Thursday. All twelve are employees of the Moa Bay Mining Company, on the north coast of Oriente. Two civilians, an American and a Canadian, were kidnaped last night.

 Mine Is Not guarded

 The Americans seized today are Sherman Avery White and J. Andrew Poll, administrator general and assistant administrator general, respectively, of the Nickel Prospecting Company, which leases the Nicaro plant from the United States Government. They were carried off at 8:30 this morning by a group of eight rebels, according to the announcement of the United States Embassy.
 No details are available, but it is supposed that the two officials went to the mine, about twelve miles from the small town of Nicaro, where 6,000 workers and officials live, to check on operations. Presumably they were abducted there. The entrance of the town is guarded by an army detachment, but the mine has no protection, it is said.
 The Moa Bay Mining Company, a subsidiary of Freeport Texas Company of New York, is situated on the north coast of oriente Province about thirty miles from the Nicaro plant. An investment of $78,000,000 is being made in the development and 2,500 Cuban workmen are employed there daily on construction work.
 The personnel from the United States Naval Base at Guantanamo were kidnaped Friday and Saturday nights on the road from Guantanamo to the small port of Caimanera, where naval personnel embark on launches for the base across the bay.
 An American spokesman said that Desmond Elmore, field superintendent of the sugar mill Ermita, near Guantanamo, also was carried off by rebels last Thursday. The Canadian Embassy here confirmed today that Richard Sargent, manager of the sugar mill. Isabel, also near Guantanamo, was kidnaped by a group of rebels last Friday.
 A spokesman of the United States Consul, Park Wollam, now in the hills near the Moa Bay property, had established contact with the rebels who kidnaped the ten Americans and two Canadians from the mining development and was exchanging messages with what the rebels call “higher headquarters.”
 Meanwhile, reports reached Havana that an expedition of 200 men and a shipment of arms landed on the south coast of Oriente the night of the kidnaping of the Moa Bay technicians. The point of debarkation was not identified. The arms were reported taken into Sierra Maestra, site of rebel headquarters.