Seven people were arrested on accusations of "providing support for the terrorist team," according to reports carried Saturday by two online news agencies for Iranian television and the judiciary in Alborz province.

By Friday, authorities had already announced the arrests of 41 suspected accomplices in connection with the attacks by five armed men on Tehran's parliament complex and the shrine of the late Ayatollah Ruhollah Khomeini.

Two guards, 10 government staffers and five civilians were killed.

As the 17 victims were buried on Friday, Iran's current Shiite leader, Ayatollah Ali Khamenei, and parliamentary speaker, Ali Larijani, directed blame at the United States and Saudi Arabia - the nation's fiercest regional rival.

On Thursday, Iran's Intelligence Ministry claimed that all five attackers had fought for the Islamic State (IS) group in Iraq and Syria and described them as being "long affiliated with the Wahhabi," a form of Sunni Islam practiced in Saudi Arabia.

Analysts suggest that the twin attacks in Iran by IS, whose members are largely Sunni, reflect the shrinkage of the group's "caliphate" in Syria and Iraq under diverse pressure from Shiite militias and airstrikes by a US-led coalition.

'A deep conflict'

Saturday's reported arrests in Iran followed a call by US Secretary of State Rex Tillerson for "no further escalation" in the region's parallel crisis, centered on Qatar.

Since Monday, Qatar has faced a Saudi-led blockade and denied funding terrorists - a charge leveled again on Friday by US President Donald Trump.

Navy Captain Jeff Davis, a spokesperson for the Pentagon, said diplomatic turmoil over Qatar had not caused interruptions at al-Udeid, a large air base in Qatar that the United States uses for military operations in Iraq, Syria and Afghanistan.

On Wednesday, German Foreign Minister Sigmar Gabriel warned that Trump's recent utterances on the Middle East were extremely dangerous.

"A deep conflict between neighbors is actually the last thing we need," Gabriel told the German business newspaper Handelsblatt.

Gabriel was subsequently and separately visited by the foreign ministers of Saudi Arabia and Qatar.

"We firmly believe that now is the hour of diplomacy," Gabriel said.

ipj/mkg (Reuters, AP, AFP, dpa)