Cairo: Egyptian police have raided the office of the Qatari news TV in Cairo and arrested 11 Qataris allegedly for illegal operation and residence amid tensions between the two Arab countries.

The late Wednesday crackdown, the latest on the station’s bureau in Egypt, came upon a tip-off that firearms were stashed away in the office in the Cairo quarter of Dokki, reported the semi-official newspaper Al Ahram.

Police did not find the alleged arms, but seized unlicensed transmission equipment and tapes, said Al Ahram.

Four of the 11 arrested staffers were released on Thursday after investigations showed that their stay in Egypt is legal, said security sources. The others are still held for further questioning. There was no comment from the Qatari embassy in Cairo.

Egyptian officials and media have repeatedly accused Al Jazeera of being biased to president Mohammad Mursi of the Muslim Brotherhood whom the army deposed in July following enormous street protests against his one-year-old rule.

The broadcaster closed its office in Cairo after police raided it and temporarily arrested some of its employees in the wake of Mursi’s overthrow.

In September, an Egyptian court ordered the closure of Al Jazeera Mubasher Misr, an affiliate of Al Jazeera, citing operation with licence.

However, Al Jazeera and its affiliate continue to extensively cover anti-military protests in Egypt and hosting Brotherhood dissidents and sympathisers. Denying the bias charge, Al Jazeera has accused Egyptian authorities of jamming its transmission.

The Egyptian government’s responses to Al Jazeera coverage have been fluctuating over the past years. Cairo briefly closed the station’s office at the peak of 2011 protests that eventually forced long-time president Hosni Mubarak out of power.

When Mursi became Egypt’s first democratically elected president in mid-2012, Al Jazeera received a preferential treatment from his government, often interviewing him and senior Brotherhood officials.

Qatar was the only one Gulf country that offered lavish political and financial backing to Mursi’s short-lived rule.

In a sign of growing strains, Egypt’s military-backed authorities have recently returned to Qatar deposits totalling 1 billion (Dh3.67 billion) — offered when Mursi was in office — after Doha refused to renew them upon their maturity.