WASHINGTON/PARIS - The Pentagon is readying more intense and longer attacks on Syria than originally planned, set to last three days, the Los Angeles Times reported Sunday.

War planners now aim to unleash a heavy barrage of missile strikes to be followed swiftly by additional attacks on targets that may have been missed or remain standing after the initial launch, the Times cited officials as saying.

Two US officers told the newspaper that the White House has asked for an expanded target list to include “many more” than the initial list of around 50 targets.

The move is part of an effort to obtain additional firepower to damage Syrian President Bashar al-Assad’s dispersed forces.

Pentagon planners are now considering using Air Force bombers, as well as five US missile destroyers currently patrolling the eastern Mediterranean Sea, to launch cruise missiles and air-to-surface missiles from far out of range of Syrian air defenses, according to the report. The USS Nimitz aircraft carrier strike group with one cruiser and three destroyers positioned in the Red Sea can also fire cruise missiles at Syria.

“There will be several volleys and an assessment after each volley, but all within 72 hours and a clear indication when we are done,” an officer familiar with the planning told the Times. The intensified military planning comes as President Barack Obama prepares to personally make his case to the American people and further press reluctant lawmakers on the need for action after Assad allegedly used chemical weapons on his own people last month.

Obama is scheduled to tape interviews Monday with anchors of the three major broadcast networks, as well as with PBS, CNN and Fox News.

The interviews, to air that night, will precede Obama’s address to the nation Tuesday ahead of an expected full Senate vote.

The president favors a limited attack with only a reduced number of warplanes to drop bombs over Syria, according to the Times.

Amid doubts that a limited US offensive would sufficiently hamper Assad’s military capabilities, one officer told the newspaper that the planned operation would amount to a “show of force” over several days that would not fundamentally change the situation on the ground.

The planned US strike “will not strategically impact the current situation in the war, which the Syrians have well in hand, though fighting could go on for another two years,” another US officer said.

US Secretary of State John Kerry continues a diplomatic offensive in Europe on Sunday to win backing for military strikes in Syria, after Washington and Paris said support for action was growing.

Heading into a crucial week for US plans to launch the strikes, Kerry was meeting with Arab League ministers in Paris and was set to head to London next before returning to Washington on Monday to continue rallying support at home.

The US Congress returns from its summer break on Monday to consider President Barack Obama’s plans for strikes and UN inspectors are to release a report into an alleged chemical weapons attack by the weekend.

Fighting continued to rage inside Syria, with reports that rebel forces had taken control of the historic Christian town of Maalula, north of Damascus.

Washington accuses the Assad regime of gassing more than 1,400 people to death in an August 21 attack outside Damascus and wants to launch punitive strikes.

On Saturday, Kerry and French Foreign Minister Laurent Fabius insisted that international support for military action was increasing, after the EU issued a statement calling for “strong” action against Syrian President Bashar al-Assad’s regime.

The EU statement did not call for military action but did condemn the “cynical use of chemical weapons.”

Kerry said Saturday he was “encouraged” by the “very powerful statement” made by the 28-nation bloc.

More nations were getting behind the need for military action and the number of countries ready to take part was now in the “double digits”, he said.

Obama, who is set to address the nation on Tuesday, is facing an uphill battle to convince a sceptical Congress — and a war-weary US public — of the need for action. According to a Washington Post survey, 224 of the current 433 House members were either “no” or “leaning no” on military action as of Friday. A large number, 184, were undecided, with just 25 backing a strike.

On Saturday, a US congressional panel posted graphic videos of what senators were told were Syrian victims of the August attack, many of them children.

The 13 videos were shown to members of the Senate Intelligence Committee on Thursday, according to the panel’s website.

US broadcaster CNN also aired the videos, with excerpts showing convulsing children and men sprawled on the floor vomiting and foaming at the mouth.

Meanwhile, Syrian rebels, including jihadists linked to Al-Qaeda, have taken control of the historic Christian town of Maalula, north of Damascus, a watchdog and a resident said on Sunday.

Maalula is home to around 5,000 residents and is of strategic importance for the rebels, who are trying to tighten their grip around the capital Damascus, adding a northern post to existing bases in the south and west of the city.

Capturing the town, around 55 kilometres north of the capital, could also help rebels threaten the nearby highway between Damascus and Homs, a supply route used by the regime.

The battle for the town left at least 17 rebels dead and more than 100 wounded overnight, the Syrian Observatory for Human Rights said, adding that dozens of regime forces and pro-militia members were also killed or wounded in the fighting.

“Overnight, Syrian regime troops moved into the village, but rebel forces sent reinforcements and were able to take control of the entire town,” Observatory director Rami Abdel Rahman told AFP.

He said the Al-Nusra Front, which has pledged allegiance to Al-Qaeda leader Ayman al-Zawahiri, was among the forces that had taken control of the town.

A Maalula resident, reached by phone, confirmed that regime forces had withdrawn from the area and rebel forces were now in control. Speaking on condition of anonymity, the resident said the situation on the ground was quiet.

“The rebels are inside Maalula, all of Maalula. The government troops have pulled out of Maalula,” the resident said.

Abdel Rahman said “fierce fighting broke out between regime forces and rebel fighters overnight, and the soldiers withdrew to the outskirts of the town.”

Troops were still stationed around the town, raising the possibility of renewed fighting.

Picturesque Maalula is nestled under a large cliff and is considered a symbol of the Christian presence in Syria.

Many of its inhabitants speak Aramaic, the language spoken by Jesus Christ that only small, scattered communities around the world still use.

It is full of troglodyte caves dating back to the first centuries of Christianity, and also houses the Mar Takla Greek Orthodox monastery.

The clashes first erupted on Wednesday, when Al-Nusra Front fighters and other Islamist rebels attacked a regime checkpoint at one entrance to the town.

The advance raised fears of attacks against churches or Christians in the town but on Friday, the opposition Syrian National Coalition said rebels had withdrawn from the area.

On Saturday, the Observatory said rebel forces were fighting pro-regime militias in the west of the town, and were also engaged in clashes with Syrian troops on the outskirts of Maalula.