* Somali pirates seize ship carrying weapons
* Also attack oil tanker north east of Seychelles
* EU force says that attack furthest yet from Somalia
* Gunmen expect Spain to free jailed colleagues
(Updates with pirate quotes, paragraphs 5-6)
By Abdi Guled and Abdi Sheikh
MOGADISHU, Nov 9 (Reuters) - Somali pirates have seized a United Arab Emirates-flagged cargo ship loaded with weapons bound for the anarchic Horn of Africa nation in contravention of a U.N. arms embargo, maritime experts said on Monday.
Also on Monday, the gunmen launched their longest range hijack attempt yet -- opening fire on a giant Hong Kong-flagged crude oil tanker 1,000 nautical miles east of Mogadishu.
Andrew Mwangura of the East African Seafarers' Assistance Programme told Reuters he believed the weapons ship was using a fake name. He said it had been hijacked on Sunday and was now held near the northern Somali town of Garacad.
"She is one of the regular weapons carriers circumventing the U.N. arms embargo on Somalia," Mwangura said. Maritime sources say the craft is believed to be carrying light arms and ammunition, as well as rockets and rocket-propelled grenades.
"We understand the weapons belong to the Somali government," Farah, a pirate, told Reuters by satellite telephone.
Another gang member, Hassan, said the weapons ship was well known to them: "It has been circling in our ocean for a long time, bringing illegal weapons to massacre Somalis," he said.
Somalia has been torn by 18 years of civil war and hardline Islamist insurgents linked to al Qaeda are fighting to topple President Sheikh Sharif Ahmed's fragile U.N.-backed government.
Some 19,000 civilians have died since the start of 2007 and more than 1.5 million have been driven from their homes, triggering one of the world's worst humanitarian disasters.
Somalia's pirates have no overt links to the country's hardline rebels but some southern pirate ports are in insurgent-held areas, and experts say there may be cooperation between some sea gangs and some rebels.
In the latest pirate attack, the European Union naval force EU Navfor said gunmen opened fire on a Hong Kong-flagged, 330 metre (1,080 ft), 160,000 tonne crude oil tanker, the BW Lion.
The attempted hijacking took place about 400 nautical miles northeast of the Seychelles and 1,000 nautical miles east of the Somali capital Mogadishu, EU Navfor said.
"This was the longest range of a pirate attack off the Somali coast ever," it said in a statement.
Mwangura said the tanker had caught fire after being hit by automatic bullets and a rocket-propelled grenade, but there were no casualties and the captain had steered his ship to safety.
"There have been 12 pirate events in this area in the last 30 days. There is a high probability of attacks in this area for at least the next 24-48 hours. Weather conditions are expected to remain favourable for piracy...through this period," he said.
DEAL TO FREE SPANIARDS?
Seasonal monsoon rains brought a lull in hijackings but the pirates have stepped up their attacks in recent weeks and now hold at least 11 vessels and more than 200 crew.
A deal to free the 36 crew members of Spanish fishing vessel Alkrana held hostage since Oct. 2 could be on the cards, Spanish Prime Minister Jose Luis Rodriguez Zapatero said on Monday.
"The government thinks that the (hostage) situation could be on the road to a solution," he told reporters in Poland.
Earlier on Monday, the first mate of the Basque tuna boat, speaking from on board the Alakrana, said that he understood Spain's government had agreed to send two accused pirates back to Somalia in exchange for the crew's release.
"It seems almost certain that they are going to send the (captured) pirates here," Ricardo Blach told Spanish state radio. "We want to believe it, good news, even if it's clutching at straws, because of the tension we have here."
The Spanish navy captured the two Somalis soon after pirates overran the Alakrana on Oct. 2 and took its crew hostage. They are set to face trial in Spain for kidnapping.
The pirates holding the crew have said they will not negotiate a ransom for their release until Spanish authorities free their two colleagues.
"In the morning (on Sunday), they were telling us in signs that they were going to cut our throats. Now the head of the pirates is smiling," Blach said in the Spanish daily El Mundo.
Environment Minister Elena Espinosa told state TV the Spanish government was exploring various options. Judge Baltasar Garzon, who ordered the two suspects be brought to Spain, told Europa Press agency that Madrid should not cave into pressure.
"I believe there are legal ways to find a solution to this conflict and without a doubt that is going to happen," he said.
The pirates said last week they had taken three men from the Alakrana ashore. But Spanish Foreign Minister Miguel Angel Moratinos said he believed the whole crew remained on board. (Additional reporting by Sarah Morris and Teresa Larranz in Madrid and Michael Holden in London; Writing by Daniel Wallis; Editing by Giles Elgood)