Iraqi forces have for the first time entered the eastern outskirts of Mosul, as they attempt to drive Islamic State (IS) militants from the northern city.

Elite Counter-Terrorism Service troops seized control of the state television building in Kukjali hours after launching an assault on the area.

Units of the army’s ninth division are meanwhile said to be bearing down on south-eastern districts of the city.On Monday, Iraqi Prime Minister Haider al-Abadi told the 3,000 to 5,000 militants believed to be inside Mosul, which they overran in June 2014, that there was “no escape” and to “either surrender or die”.

About 50,000 Iraqi security forces personnel, Kurdish fighters, Sunni Arab tribesmen and Shia militiamen are involved in the two-week-old offensive to drive IS militants out of their last major urban stronghold in the country.

CTS units retook Bazwaya, the last village before Mosul’s eastern outskirts, in a dawn assault on Monday and then advanced on the Kukjali industrial zone.They moved out again shortly before first light on Tuesday, this time with the aim of entering the adjoining Kukjali residential area, which is within the city limits.If the troops can establish a foothold inside Mosul, it will be a big day for Iraq and all the other countries involved in the fight against the jihadist group.However, they are coming up against much more fierce resistance than he has seen in the past few days.The troops have responded to the RPG, machine-gun and sniper fire with heavy weapons, and also by calling in air strikes by the US-led coalition against IS.

A number of civilians have also approached them, some waving white flags.

The Iraqi military announced on Tuesday that the ninth armoured division was approaching the south-eastern districts of Somer, Palestine, Yarimjah and Intisar, having recaptured the outlying villages of Allag, Tahrawah and Tubraq Ziyarah.

Federal police meanwhile recaptured four villages about 25km (15 miles) to the south of Mosul, and the 16th infantry division made further gains to the north. Shia-led paramilitary Popular Mobilisation forces took a number of villages in the desert about 18km (11 miles) south-west of Mosul, as they seek to seal off western escape routes from the city, according to the military.

As Mosul is encircled, UN officials have expressed concern for the safety of the 1.5 million civilians estimated to be living there.

The Office of the High Commissioner for Human Rights said on Tuesday that it had received fresh reports of mass killings and forced relocations carried out by IS. Militants were alleged to have killed 40 former soldiers from the Shura area south of Mosul and from villages surrounding the town of Hamam al-Alil, and then thrown their bodies into the River Tigris, spokeswoman Ravina Shamdasani said.

IS also brought dozens of lorries and mini-buses into Hamam al-Alil early on Monday in an attempt to forcibly transfer 25,000 to the city itself, she added. Many of the vehicles were prevented from moving by coalition military operations in the area. But some did reach Abu Saif, just outside Mosul’s international airport.

More than 17,900 people have fled Mosul since the offensive began. According to the UN’s worst-case scenario, as many as 700,000 others could follow suit.