Yemen has had to raise its imports of fuel, buying another seven cargoes since last week, a shipping source said on Wednesday, as its biggest refinery was forced to shut due to lack of crude flow from its main pipeline.

"They've been receiving supplies of gasoline, diesel into Hudaida and Aden. At least seven vessels have come to Hudaida since the middle of last week," the source said.

The cargo sizes were around 15,000 to 20,000 tonnes as the coastal terminal of Hudaida handles smaller tankers.

Yemen bought 15,000 tonnes of diesel and 30,000 tonnes of gasoline from Saudi Arabia last week, after a blast on its main oil pipeline halted crude flow from Marib oilfields to its biggest Aden refinery.

The Arabian Peninsula state has been rocked by months of protests, demanding the immediate departure of President Ali Abdullah Saleh, who has been in power for over three decades.

The country normally imports around 30,000 tonnes of oil products per month, but Aden refinery opened a spot tender last week to buy 105,000 tonnes of jet fuel, gasoline and gas oil.

Two traders said the tender was not awarded as traders were reluctant to supply due to Yemen's credit issues. "I heard there are at least 4-5 ships offshore, which can't discharge because of credit problems," one Gulf based gasoline trader said.

Light crude exports shut

The credit problems are unlikely to go away, another  Gulf-based trader said, with nearly half of the country's oil production remaining shut.

"There is still no oil coming down from Marib," a second Yemen-based shipping source said. "And there are no exports out of Ras Isa," he added.

Yemen produces around 280,000 barrels per day (bpd) of crude oil. Of that, around 110,000 bpd is light crude, which is in short supply globally after the loss of Libyan output in February.

The pipeline blast occurred in the central Marib province, where several oil and gas fields operated by international companies are located.

Austria's OMV is among companies which stopped producing out of Yemen following the pipeline blast. The company was exporting its light crude out of Ras Isa.

Separately, Canadian oil producer Nexen halted its oil output in Yemen on Sunday night due to a labour disruption.

The company, Canada's No. 6 independent oil producer, produces about 70,000 bpd of oil in total in Yemen.

On Wednesday, another Yemen-based shipping source said the 130,000 barrels-per-day Aden refinery was receiving crude via land, but this could not be immediately confirmed. – Reuters