Armed police have evacuated an apartment block in Sheffield city centre over fears a man inside has explosives and weapons.<br /><br />Residents of The Gateway flats were ordered out at 7.20pm on Monday and sent to a sports centre two miles away.<br /><br />Nearby buildings remain on lockdown, and a 300-metre stretch of the city’s ring road is closed, causing major disruption.<br /><br />Police are negotiating with the man, who allegedly made threats.<br /><br />South Yorkshire Police have urged the public to avoid the area while emergency services continue their work.