Yemeni President Ali Abdullah Saleh ordered the arrest of the powerful opposition tribal leader Sadiq al-Ahmar, while fresh violence hit Libya Thursday.

The Yemeni Defense Ministry said Thursday that "the president has ordered the public prosecution to bring dissident Sadiq al-Ahmar and his nine brothers to justice for waging armed rebellion against the state."

Al-Ahmar is the chieftain of the powerful tribal coalition Hashed, which is behind the chronic nationwide anti-government protests.

Meanwhile, at least 28 tribal militants were killed in an explosion at a weapons storage facility overnight Thursday in Yemen's capital Sanaa.

The Defense Ministry's website said the militants were loyal to al-Ahmar.

"The arms storage contained a large quantity of small and heavy weapons, including rocket-propelled grenades and different kinds of missiles and shells, which were used in attacking residents and occupying government buildings," the ministry said.

It also said the government forces destroyed the opposition satellite TV station Suhail in Hassaba district in downtown Sanaa. The station was owned by one of al-Ahmar's brothers Hamid al-Ahmar, who is also a prominent figure in the opposition Islamic Islah Party.

However, residents and eyewitnesses said the shells destroyed two nearby houses, while no shell hit the headquarters of the opposition TV station.

Non-stop clashes continued to rock the Hassaba area. An opposition official told Xinhua that at least 79 of al-Ahmar's fighters were killed during the overnight clashes, warning of more fierce clashes by al-Ahmar's fighters against government forces.

Thursday marked the fourth consecutive day of street battles between al-Ahmar's armed guards and government forces.

The street war, after President Saleh's refusal to sign a Gulf Cooperation Council-brokered deal, erupted Monday when the tribal forces stormed and occupied several government buildings and ministries.

The four-day-old street battle has left hundreds of people dead.

The capital's residents have been leaving in large numbers for the remote countryside in other provinces due to the intensification of random bombings.

In Libya, five powerful explosions struck the area where Libyan leader Muammar Gaddafi has his residence after NATO air raids earlier in the week, in the capital Tripoli.

Meanwhile, forces loyal to Gaddafi bombarded the rebel-held city of Misrata with mortars.

The bombardment of Misrata was the heaviest in days. It came as Western leaders are attending a Group of Eight summit from Thursday to Friday in the French seaside resort of Deauville, at which they are expected to repeat their determination to force Gaddafi out.

The British government has given the green light to putting the country's Apache attack helicopters at NATO's disposal for use in Libya.

The European Union (EU) welcomed the decision by the Libyan ambassador to the bloc Al Hadi Hadeiba "to sever links with the Gaddafi regime," saying other senior officials of the regime should follow suit.

Hadeiba had announced earlier Thursday that he was defecting along with all his staff from the Tripoli government.

"We have been in contact with him (Hadeiba) and praise his courageous decision to work for a democratic Libya and a better future for the Libyan people," EU Foreign Policy Chief Catherine Ashton said.

She said the EU looked forward to remaining in close contact with Hadeiba.

Hadeiba is the latest high-profile official to defect from the Gaddafi-led government, after Libyan Foreign Minister Moussa Koussa turned against Tripoli and flew to Britain in March.

"Those at the top of the Gaddafi regime have a choice: stay with Gaddafi and face rejection by their fellow citizens and the international community," said an EU statement following Hadeiba's defection.

Nevertheless, more than three months into the unrest in the oil-rich North African country, there is still no quick end in sight for the military deadlock as Gaddafi has shown no signs of giving in, despite increasingly fierce NATO air attacks on Tripoli.