Fierce ground battles have been rocking the northern part of the Yemeni northern province of Saada for the first time since the civil war erupted in the impoverished Arab country more than two years ago, provincial sources said on Saturday. Dozens of villagers were seen fleeing their homes and farms towards southern safe districts to escape randomly artillery and tanks' heavy shelling, as well as intense airstrikes.

The ongoing battles were raging between the government forces of exiled Yemeni President Abd-Rabbu Mansour Hadi backed by warplanes from a Saudi-led coalition and their foes of Shiite Houthi rebels who seized north of the country after forcing Hadi and his internationally-recognized government into exile.

The government troops were trying to advance for the first time to control the main stronghold of the leader of Houthi group, Abdulmalik al-Houthi. A military source said on Saturday that the "government forces have advanced deep inside the rebel Shiite Houthi key stronghold" in the northern border province of Saada as the clashes are ongoing.

He said the troops have seized control over several mountainous territories during their coalition-backed advance over the past few days, tightening siege on the militias after days of fierce battles.

The battles began last week after the government troops, backed by heavy airstrikes from the Saudi-led coalition warplanes, launched a large-scale ground offensive simultaneously from three sides, advancing from nearby Saudi border region of Najran towards the north, west and east of Houthi stronghold district of Baqim.

In the operation, the military source said the troops seized control over the highlands of al-Khashm north of the district, al-Nimsa to the east and as al-Sabhan to the west, cutting off the militias' supply lines from the three sides surrounding the district.

"Baqim now is under tightened siege from the north, east and the west," said the source on condition of anonymity. Baqim locates at the far north of Saada and is considered the northern gate to the rest areas of the province. "The militias have retreated after suffering heavy casualties but the clashes were still ongoing," the source said without giving a specific number of losses from both warring forces.

Meanwhile, the Houthi group did not release any report on its media regarding the attack. Saada is about 242 km northwest of the capital Sanaa, which is also under control of Houthi fighters. Battles between the warring forces were also raging on several other front lines in nearby provinces of Hajjah, al-Jawf, al-Baydha, Shabwa and Taiz.

Yemen's internationally-backed government, allied with the Saudi-led Arab military coalition, has for more than two years been battling Iran-backed Shiite Houthi rebels over control of the country. The coalition began a military air campaign in March 2015 to roll back Houthi gains and reinstate exiled President Abd-Rabbu Mansour Hadi to the power.

The coalition also imposed air and sea blockade to prevent weapons from reaching Houthis, who had invaded the capital Sanaa militarily and seized most of the northern Yemeni provinces since late of 2014. More than 10,000 people, most of them civilians, have been killed in the war that also displaced around three million. The impoverished Arab country is also suffering the world's largest cholera epidemic since April, with about 5,000 cases reported every day.

On the other hand, Houthis have tightened the noose on journalists associated with former Yemeni President Ali Abdullah Saleh after besieging them to choose between speaking in support of a united rhetoric or keeping silent.

The latest Houthi threat came in light of the dispute that erupted last month between both parties.

Yemen’s Minister of Information Muammar al-Iryani told Asharq Al-Awsat on Friday that “the general behavior of Houthis with journalists is marked by exclusion. The rebel groups do not miss a chance to silence any voice that does not respect their ideologies, even if their moves were at the expense of their partners in the coup.”

The minister said Houthis should release all prisoners, especially journalists.

Yemeni political analyst Najib Gholab explained that Houthis were currently expanding their threatening approach.

“They arrested some journalists and threatened others. Journalist Nabil al-Soufi who is close to Saleh, already announced that he will not speak about politics, and cynically said he will talk about cooking and fashion in order to avoid being arrested,” Gholab said.

He said that several social media activists considered the fact of submitting to the threats as not a right decision.

Yemeni political analyst Abdullah Ismail told Asharq Al-Awsat on Friday that “Houthis have started early to target pro-Saleh journalists,” adding that those insurgents do not accept any kind of criticism.