JERUSALEM — The mayor of Haifa ordered on Sunday the closure of plants run by Israel’s largest refining and petrochemicals group, Oil Refineries, following a report showing high cancer rates in the port city.

Oil Refineries said its operating license and that of a number of its subsidiaries had been canceled in Israel’s third largest city, which is heavily industrialized. The company said it thought the order was illegal and vowed to take legal action.

A report issued by the Health Ministry last week said that data collected over the past decade showed a higher rate of cancer in the Haifa area compared to the national norm, possibly because of bad air pollution.

“(The plants) will close (tomorrow) and if the state wants matters to be put back on track, it must come and explain the report to us,” Haifa Mayor Yona Yahav told Israeli television.

In a statement to the Tel Aviv Stock Exchange on Sunday, Oil Refineries, which is controlled by conglomerate Israel Corp., said it had received notices from the mayor’s office confirming the cancellation of its business licenses.

It said it believed “the mayor’s notices were issued without authorization and they are without any basis and are not empowered in law.” It added that it intended to fight the order in the courts.

Oil Refineries can refine some 9.8 million tons of crude oil a year at its Haifa plant and is one of the biggest firms in the city. Company shares fell 2.8 percent on Sunday.

The firm said it had invested over a billion shekels, or about $250 million, to reduce harmful emissions from its installations and to clean up the local environment.

The Health Ministry report said that in the period 1998-2007, cancer among children and youths under 19 in Haifa was higher than the national average, but the findings were not clear cut. It also said there was a higher-than-national average for cancers believed to be caused by air pollution.