New York police believe Iranian Revolutionary Guards or their proxies have been involved so far this year in nine plots against Israeli or Jewish targets around the world, according to restricted police documents.

Reports prepared this week by intelligence analysts for the New York Police Department (NYPD) say three plots were foiled in January, three in February and another three since late June. Iran has repeatedly denied supporting militant attacks abroad.

In another development, a lawmaker said just over half of Iran’s parliament has backed a draft law to block the Strait of Hormuz, threatening to close the Gulf to oil tankers in retaliation against European sanctions on Iranian crude.

Lawmaker Javad Karimi Qodoosi said 150 of parliament’s 290 members had signed the bill, describing the strait as “the world’s lock” to which Iran holds the key. “If the sanctions continue, the countries that have imposed sanctions have no right to cross the Strait of Hormuz without harm,” the Iranian Students’ News Agency quoted Qodoosi as saying. “From a military standpoint, the power to close the Strait of Hormuz is 100 per cent there ... if we close the Strait of Hormuz, no country will be able to open it”.

The New York police documents, labelled ‘Law Enforcement Sensitive’, said this week’s suicide bomb attack in Bulgaria was the second plot to be unmasked there this year.

The reports detail two plots in Bangkok and one each in New Delhi, Tbilisi, Baku, Mombasa and Cyprus. Each plot was attributed to Iran or Hezbollah, said the reports, which were produced following the bombing in Burgas, Bulgaria of a bus carrying Israeli tourists.

Iran on Thursday dismissed “unfounded statements” by Israel linking Teheran to the Burgas blast, saying they were politically motivated accusations which underscored the weakness of the accusers.

Wednesday’s bombing in the Black Sea city is listed in a document headed ‘Suspected Iranian and/or Hezbollah-linked Plots Against Israeli or Jewish Targets: 2012 Chronology’, the latest of the nine 2012 plots linked to the Islamic Republic or its proxies.

US officials say they increasingly concur with Israeli assessments that Iran and its proxies organised the killing of seven Israeli tourists in Burgas by a suicide bomber after they boarded an airport bus.

One US official said Hezbollah had in the past carried out suicide bombings.

The official said the Bulgaria attack appeared relatively sophisticated as it suggested those behind it had gathered intelligence on possible targets in advance.

A second US official said US federal authorities’ tally of alleged Iran-linked plots in 2012 largely paralleled the NYPD list.