TEHRAN — Iran's Foreign Ministry summoned the Azeri ambassador Sunday, accusing Azerbaijan of assisting Israeli intelligence in the assassination of an Iranian nuclear scientist last month, Iran's Fars news agency reported.

Mostafa Ahmadi-Roshan was killed when two men on a motorcycle attached a magnetic bomb to his car on Jan. 11. The 32-year-old worked at the Natanz uranium enrichment facility.

At least four scientists associated with Iran's nuclear program have been assassinated since 2010, and a fifth was wounded in a bomb attack. Iran's Supreme Leader, Ayatollah Ali Khamenei, called Ahmadi-Roshan's killing a "cowardly act" and accused the United States and Israel of responsibility.

Iran says its nuclear program is peaceful, but Western countries say it is aimed at building a nuclear bomb.

Israeli officials have not commented on whether they are behind the killings of Iranian scientists but have made clear that they are pleased. Washington criticized the killing of Ahmadi-Roshan and denied blame.

The semi-official Fars news agency quoted the Iranian Foreign Ministry's press office as saying the Azeri ambassador, Javanshir Akhundov, was summoned because Azerbaijan had helped agents to get in contact with the Israeli intelligence agency.

According to the report, Akhundov was also rebuked over the mistreatment of Iranian officials in Azerbaijan and Iranian trucks having difficulties entering the country.

Azerbaijan, a secular Muslim country bordering Iran, has friendly ties with the United States and Israel and has had difficult diplomatic relations with Tehran. Iran is home to a large ethnic Azeri minority.