Iraqi troops backed by US-led air strikes have pushed deeper into eastern Mosul after a two-week lull in the operation to retake the city held by the Islamic State of Iraq and the levant (ISIL, also known as ISIS) group.
Staff Lieutenant-General Abdulghani al-Assadi, a senior officer in Iraq's counterterrorism service, said the second phase of the  operation, now in its third month, began on Thursday.
He told the AFP news agency that forces began advancing towards the Quds neighbourhood.
"Now our forces clashed with the enemy and there is resistance," al-Assadi said, adding that forces on the northern and southern fronts were also advancing.
READ MORE: Battle for Mosul - 'I miss everything there'
Special elite forces also pushed into the Karama neighbourhood, while army troops and federal police advanced into nearby Intisar, Salam and Sumor neighbourhoods, the AP news agency reported.
Smoke rose across the city as explosions and machine-gun fire echoed through the streets.
The counterterrorism forces, also known as the Golden Brigade, captured about half of the Quds neighbourhood by early afternoon.
Stiff resistance by ISIL fighters, together with civilians trapped inside their houses and bad weather have slowed advances in the offensive to recapture Iraq's second largest city, the armed group's last urban bastion in the country.
A statement by the US-led coalition said Thursday's offensive opened two new fronts in eastern Mosul, increasing pressure on ISIL's "dwindling ability to generate forces, move fighters or resupply".
Mosul humanitarian crisis: Aid groups appeal for more resources
It said that, at the request of the Iraqi government, coalition warplanes had "re-struck" two bridges over the Tigris River in Mosul on Tuesday, and a day earlier "disabled" the last bridge crossing in the city.
"The strikes were conducted to reduce enemy freedom of movement, and to further disrupt ISIL's ability to reinforce, resupply, or use vehicle-borne improvised explosive devices in East Mosul," said the statement.
Another coalition statement said an air strike on Thursday that targeted a van used by ISIL fighters in Mosul was later determined to have been located at a hospital's parking lot, "resulting in possible civilian casualties".
The coalition, it added, "takes all allegations of civilian casualties seriously and this incident will be fully investigated and the findings released in a timely and transparent manner."
It was not immediately known how many, if any, were hurt by the air strike.

Biggest operation

It is the biggest Iraqi military operation since the 2003 US-led invasion.
ISIL overran large areas north and west of Baghdad in 2014, but Iraqi forces, backed by US-led air strikes, have since regained much of the territory they lost to the group.
Iraqi Prime Minister Haider al-Abadi had pledged that Mosul would be recaptured by year's end. That goal that is now out of reach, as operations in western Mosul have yet to begin.
Abadi said earlier this week that three months were needed to eliminate ISIL in Iraq.
However, Lieutenant-General Stephen Townsend, the general commanding coalition forces in Iraq, predicted that it would take two years to clear ISIL from Mosul and Raqqa, and then to burn out the remnants of the group.