ZURICH (Reuters) - Switzerland has added 116 names to its list of Iranian entities under sanctions, in response to heightened international concern about Tehran's nuclear ambitions. The 35-nation board of the UN. nuclear watchdog looked set on Friday to censure Iran over mounting suspicions it is seeking to develop atom bombs. Last week's International Atomic Energy Agency (IAEA) report presented a stash of intelligence indicating Iran had undertaken research and experiments geared to developing a nuclear weapons capability. That redoubled calls in Western capitals for stiffer sanctions. The new sanctions against five people and 111 organisations will come into force with immediate effect, the government said. Earlier this year the Swiss government brought its Iran sanctions into line with its main trading partner, the European Union. The Swiss prohibitions include a ban on certain financial transactions and Swiss companies selling or delivering so-called dual use goods, products which could also be used for military purposes. The United States accused Iran on Friday of a "provocative expansion" of sensitive nuclear activity and voiced concern that some nuclear material may have been diverted to suspected weapons-related development research. US Ambassador Glyn Davies made the allegation in a statement to the 35-nation board of the UN. nuclear watchdog, which later on Friday was expected to pass a resolution rebuking Iran over mounting concerns that it is seeking the capability to produce atom bombs. "Iran's covert attempts to develop undeclared pathways for the production of nuclear material and work on nuclear weapons technology leaves little doubt that Iran, at the very least, wants to position itself for a nuclear weapons capability," Davies said, according to a copy of his speech. Last week, an International Atomic Energy Agency report presented a stash of intelligence indicating that Iran has undertaken research and experiments geared to developing a nuclear weapons capability. Iran says it is enriching uranium only as fuel for nuclear power plants, not atomic weapons. It has dismissed the details in the IAEA report obtained mainly from Western spy agencies as fabricated, and accusing the IAEA of a pro-Western slant. Davies denounced Iranian plans to move higher-grade uranium enrichment work to an underground bunker near the city of Qom. "Stockpiling uranium enriched to near 20 percent is a dangerous provocation because it positions Iran to move closer to the production of highly enriched uranium in a shorter period of time," Davies said.