DOHA: Al Jazeera's signal across the Middle East and North Africa was plagued by jamming on Sunday, the Arab satellite broadcaster said, and Lebanon said the electronic interference was coming from Libya.

Al Jazeera, whose coverage of the regional political unrest has been widely watched in the Arab world, first reported jamming on Friday and said its website had been blocked in Libya.

“We believe that whoever is doing this is operating with sophisticated and large equipment,” an Al Jazeera spokesman said in a statement.

In Beirut, Lebanese Telecommunications Minister Charbel Nahhas said the jamming “originated from Libyan territory” and it was also affecting Lebanese channels.

“They (Libyans) see what these televisions carry about what is happening in their country and they jam the transmission points ... so Al Jazeera is affected and we are affected too,” Nahhas told Reuters.

There was no immediate response from Libya, where tens of thousands gathered in the city of Benghazi on Sunday for funerals of protesters killed by security forces as Human Rights Watch said overnight violence had doubled the death toll from four days of clashes to 173.

“We ... are investigating the source of the problem, though cooperation would be needed from governments to precisely determine this,” the Al Jazeera spokesman said, adding that alternative frequencies were offered to viewers.

The jamming was being caused by large installations capable of simultaneously interfering with several frequencies on the Arabsat and Nilesat satellites that carry the Qatar-based news channel's signal, it said.

The station has exhaustively covered events in Libya, Bahrain and Yemen, contacting protesters and government backers by telephone and often airing footage of events sent via the Internet.

Earlier this month, Egypt's Nilesat cut off Al Jazeera's signal for more than a week after authorities there ordered it to stop operations in Egypt during the unrest that ultimately ended President Hosni Mubarak's 30-year rule.

Launched in 1996, Al Jazeera has more than 400 reporters in over 60 countries, according to its website. It says it can reach 220 million households in more than 100 countries.