Warren Markey 2014

U.S. Sens. Edward J. Markey and Elizabeth Warren are seen at an event in Springfield last month. Both broke with President Obama's proposal Thursday to equip and train Syrian rebels to fight ISIS.

(Dave Roback / The Republican file)

BOSTON — President Barack Obama's proposal to prepare Syrian rebels for a war against Islamic State militants found little support among the members of the Massachusetts all-Democratic congressional delegation.

U.S. Sens. Elizabeth Warren and Edward Markey on Thursday broke with the president and opposed the request to train and arm the rebels for a war against Islamic state militants.

The Senate approved the request late Thursday on a 78-22 vote.

Warren said she wasn't convinced the proposal to train and equip Syrian rebels advances U.S. interests or that it would be effective in pushing back Islamic State fighters.

"I remain concerned that our weapons, our funding, and our support may end up in the hands of people who threaten the United States," Warren said in a statement. "I do not want America to be dragged into another ground war in the Middle East."

Markey — who won Secretary of State John Kerry's old Senate seat in a special election last year — said he supported Obama's and Kerry's "near-term efforts to build an international coalition and use air strikes" against Islamic State fighters to help defend Americans and our allies and "degrade the group's capacity to continue the rampant killing of innocent civilians."

But Markey said he was leery of arming Syrian rebels given the complexity of the ongoing fighting in the country.

"There are unintended consequences that may come from arming one of these factions to fight against another, including the very real risk of American weapons falling into the wrong hands," Markey said in a written statement after Thursday's vote. He added that he has "grave concerns that American military leaders have not ruled out the potential use of ground troops for combat."

After the vote Obama said he was pleased that a majority of both Republicans and Democrats had supported the legislation, adding that "as Americans we do not give in to fear," noting the killing of two Americans by the group.

In the Senate, 44 Democrats, 33 Republicans and one independent voted for the bill, while 9 Democrats, 12 Republicans and one independent opposed it.

On Wednesday the House also passed the measure on a 273-156 vote.

Just two members of Massachusetts' U.S. House delegation — congressmen Stephen Lynch and Richard Neal — backed the proposal.

Related: Congressmen Richard Neal & Stephen Lynch vote to arm Syrian rebels to fight ISIS

The rest of Massachusetts' nine-member delegation — Reps. Michael Capuano, Katherine Clark, William Keating, Joe Kennedy, James McGovern, John Tierney and Niki Tsongas — opposed it.

"This amendment is a back door vote that has the potential to lead to an expanded and open-ended commitment spilling into future administrations," Tsongas said after Wednesday's House vote.

Kennedy agreed and said the vote shouldn't be taken "lightly, quickly, or piecemeal."

Clark also said she feared the U.S. sliding into a deeper commitment without a full debate.

"The civil war in Syria is complex with volatile shifting allegiances," Clark said. "This proposal cannot be evaluated accurately without a discussion of a comprehensive strategy."