US steps up campaign against Isis with air strike near Baghdad

Obama administration expands operations against Islamic State with attack south-west of Iraqi capital

Isis militants. The US has stepped up its campaign against the group with air strikes near Baghdad. Photograph: Alamy

American warplanes have returned to the skies near Baghdad in the latest expansion of the US war against Islamic State (Isis).

For the 162nd air strike since 8 August, US fighter jets attacked an Isis position that US Central Command said was firing on Iraqi security forces. Unlike its 161 predecessors, the attack occurred "south-west of Baghdad", broadening the newest US battlefield.

The strike, which Central Command said destroyed the Isis fighting position, follows Barack Obama's vow in his televised speech on Wednesday to go on the offensive against Isis more broadly in Iraq and, soon, Syria.

The past month's worth of air strikes have focused on Isis positions further to Iraq's north and west, either near the Kurdish regional capital of Irbil; the dams at Mosul and Haditha; or Sinjar Mountain.

The Obama administration had held out the prospect of coming to Baghdad's relief in exchange for Iraq's political leaders ousting the prime minister, Nouri al-Maliki, who it considered too sectarian to continue governing.

Central Command, in a statement released on Monday evening, said the strike near Baghdad was the first "taken as part of our expanded efforts beyond protecting our own people and humanitarian missions."

A separate air strike also targeted Isis near Sinjar, where Central Command said it destroyed six Isis vehicles.

The Baghdad air strike comes as US legislators, who have so far been sidelined by Obama's efforts in Iraq, signalled a desire for greater involvement in the emerging war, some of which coincides with the administration's war planning.

Buck McKeon, the California Republican who chairs the House armed services committee, introduced an amendment to a stopgap funding measure that would authorise the Defence Department to arm and train "appropriately vetted" Syrian rebels. Obama is seeking $500m for the measure, which the Pentagon estimates could yield over 5,000 trained Syrian anti-Isis fighters in its first year.

Attaching the training authorisation to the broader funding measure, called a continuing resolution, will likely constrain the legislative debate on the US's latest military involvement in Iraq. The continuing resolution is needed to fund the government for the first months of the fiscal year, which begins 1 October.

The House committee said in a statement that the amendment would not itself fund the training, "but does allow the defence department to submit reprogramming requests to Congress," in effect shuffling money between Pentagon accounts.

On Tuesday, a different California legislator, Adam Schiff, intends to introduce a formal authorisation authorising "all necessary and appropriate force" against Isis in Iraq and Syria, except for funding non-special operations ground forces. Schiff's measure would expire after 18 months and replace the 2002 authorisation for the fateful war to overthrow Saddam Hussein –which Obama opposed as a state senator. yet last week his administration cited as a wellspring of legal authority for the latest war.

Congress will also express its views on the war on Tuesday morning when the Senate armed services committee hears from the Pentagon leadership, defence secretary Chuck Hagel and General Martin Dempsey, the chairman of the joint chiefs of staff. It will be the Pentagon officials' first formal testimony about the war.

As Hagel and Dempsey testify, Obama will meet at the White House with his newly convened team in charge of coordinating the allied effort against Isis, retired marine general John Allen and state department Iraq troubleshooter Brett McGurk. Obama plans to visit Central Command's Tampa headquarters on Wednesday to discuss the war.