JERUSALEM — Police said yesterday that they had arrested Israeli staff at two Tel Aviv companies suspected of helping channel funds to Hamas and Islamic Jihad.

Authorities raided offices of Shintrako Ltd. and Mayan Customs Brokers and International Forwarding yesterday in the Tel Aviv suburb of Ramat Gan, the police said in a statement. Police arrested the general manager of Shintrako and other employees of the two companies, the statement said.

Mayan accountant Tzvika Koren denied that anyone from the company was arrested and said police had only questioned several employees, including himself. The company was not involved in any illegal activity, since it only relayed Shintrako imports through customs, Mr. Koren said.

Shintrako did not immediately return a call requesting comment.

The companies are suspected of funding Hamas and Islamic Jihad through a company they did business with in the Gaza Strip, the statement said. Shintrako had been warned not to work with the company but found ways to help it get around trade restrictions imposed by Israel, the release said.

Police report an increase during the past year in the flow of clandestine finance to Palestinian Arab militant groups squeezed by a financial blockade imposed by international aid donors since Hamas last year won parliamentary elections and control of the Palestinian Arab government.

“These funds are used as fuel to ignite terror, and they allow these organizations to preserve and expand their organized infrastructure,” the police statement said.