Iran held a public funeral on Tuesday for a senior paramilitary fighter killed fighting in Syria, the fourth commander to die this month as Tehran intensifies its support for President Bashar al-Assad against insurgents.

Nader Hamid died in a Syrian hospital last week of gunshot wounds sustained in a gunbattle several days earlier, Iranian agencies reported. He was a member of the Basij, the volunteer arm of Iran's Islamic Revolutionary Guards Corps (IRGC).

Iranian fighters have been arriving in Syria to reinforce Syrian government troops in an offensive in the contested northern city of Aleppo and other insurgent-held areas.

Two regular IRGC senior officers were killed in an undisclosed part of Syria on Oct. 12, and a top IRGC general was killed near Aleppo on Oct. 8, according to the Tasnim news agency which is close to the Guards.

Iran says it has military advisers and volunteers in Syria but denies having a conventional force on the ground and says it is supporting the Syrian army against Islamic State insurgents. Russia, which is carrying out air strikes with Syrian-based jets, says the same.

Other rebel groups fighting both Assad and Islamic State, some of which have received U.S.-made weapons from foreign states opposed to Assad, say they have borne the brunt of the offensives in Aleppo and elsewhere.

Shi'ite Muslim power Iran frequently characterizes all Syrian opposition groups as Sunni Muslim extremists, and Tasnim said Hamid had traveled to Syria to "defend the shrine of Zaynab", a Shi'ite pilgrimage site in Damascus.

Iran accused Saudi Arabia on Tuesday of fostering extremism in the region, a day after the kingdom said Tehran's support for Assad disqualified it from playing a role in peacemaking efforts in Syria. Assad's foreign opponents include Saudi Arabia, Qatar and neighboring Turkey.

(Reporting by Sam Wilkin; Editing by Mark Heinrich)