|The uprising against Saleh is just one of the many crises gripping Yemen, where al-Qaeda has long been active [EPA]
The US has intensified air raids on suspected fighters in Yemen in a bid to keep them from consolidating power as the impoverished Gulf Arab country's government teeters, The New York Times reports.
Citing US officials, the newspaper said on Wednesday that a US campaign using armed drones and fighter jets had accelerated in recent weeks.
A US official confirmed to the Reuters news agency that a US attack last Friday killed Abu Ali al-Harithi, a mid-level al-Qaeda operative, which followed last month's attempted raid against Anwar al-Awlaki, the leader of al-Qaeda in the Arabian Peninsula.
Earlier on Wednesday, Admiral Michael Mullen, the US military commander, said the conflict in the Arabian Peninsula country was making the al-Qaeda terror network more "dangerous".
Al-Qaeda in Yemen "has grown into a very virulent deadly federated point in the al-Qaeda organisation", the head of the US joint chiefs of staff said in Cairo.
"It is incredibly dangerous and made more dangerous in the ongoing chaos."
Troops pulled back
With the country in violent conflict, Yemeni troops that had been battling fighters linked to al-Qaeda in the south have been pulled back to Sanaa, the New York Times said.
Ali Abdullah Saleh, Yemen's president, was wounded on Friday and is being treated in the Saudi capital, Riyadh.
He appears to have been wounded by a bombing at a mosque inside his palace, not a rocket attack as first thought, US and Arab officials told Reuters.
There were conflicting reports about his condition - ranging from fairly minor, to life-threatening 40 per cent burns.
Saleh, who has ruled the country for 33 years, has been a vital US ally on the "war on terror".
In Sanaa, on Wednesday, demonstrators chanted "No to Saleh's return", referring to Saleh, who was flown to Saudi Arabia for treatment on Saturday after an attack on his palace.
The New York Times said that the recent operations came nearly a year after they had been halted because of bad intelligence that had led to several civilian deaths.
According to the newspaper, Saleh had authorised American missions in Yemen in 2009, but has said publicly that all military operations were conducted by Yemeni troops.
US and Saudi spy services have been receiving more information from electronic eavesdropping and informants about possible locations of fighters, the New York Times said, citing officials in Washington.
But there were concerns that with the wider conflict in Yemen, factions might feed information to trigger air strikes against rival groups.
The operations were further complicated as al Qaeda operatives mingled with other rebel and anti-government militants, the newspaper said, citing a senior Pentagon official.
The US ambassador in Yemen recently met opposition leaders, partly to make the case for continuing operations in case Saleh's government falls, the newspaper said.
Opposition leaders have told the ambassador that operations against al-Qaeda in Yemen should continue regardless of who wins the power struggle in the capital, the New York Times said, citing officials in Washington.
Al-Qaeda's affiliate in Yemen has been linked to the attempt to blow up a trans-Atlantic jetliner on Christmas Day 2009 and a plot last year to blow up cargo planes with bombs hidden in printer cartridges.