Cyclist Lizzie Armitstead won first medal for Team GB
Cyclist Lizzie Armitstead has won Team GB's first London 2012 medal, taking silver in the women's road race.
At around 20:18 BST, swimmer Rebecca Adlington will aim to win gold in the final of the 400m freestyle.
London 2012 chairman Lord Coe has insisted Olympics venues are "stuffed to the gunnels" with sports fans.
His comments come after hundreds of seats were left empty on Saturday and Sunday morning, including swimming, rowing, tennis and basketball.
Armitstead, 23, from Otley near Leeds, was beaten to the gold at the end of the 140-kilometre race by Holland's Marianne Vos in a sprint finish on The Mall.
Elsewhere in other Olympic developments:
Paula Radcliffe has withdrawn from the marathon due to injury
Commuters have been advised to avoid London Bridge station on Monday as thousands head to south-east London for the equestrian cross country at Greenwich Park
Zara Phillips said the crowds were "amazing" as she competed in the dressage
The unidentified woman who joined the Indian delegation at the opening ceremony has been identified by Lord Coe as a volunteer performer who had got "slightly over-excited"
Three people have been charged after 182 were held following a Critical Mass cycle ride near the Olympic Park on Friday
Lord Coe spoke out as the row mounted over unfilled seats in several Olympic venues.
At some venues, seats in the accredited "Olympic family" areas - reserved for groups including officials, sports federations, athletes, journalists and sponsors - have remained empty.
"I don't think you will be seeing this as an issue, long-term through the Games," Lord Coe told a press conference.
Organisers would fill some of the empty seats with servicemen and women, as well as local students and teachers, he said.
And they would sell more tickets - as they did with about 1,000 tickets on the London 2012 website on Saturday night.
He said a system had been introduced similar to the one used at Wimbledon, where people coming out of the stadium handed on their tickets so the seats could be made available to others.
Locog said it would examine options to upgrade the tickets of members of the public and move them into accredited areas.
Tickets are also given to sponsors and, on Sunday, Visa, British Airways and Lloyds TSB all said they had given the majority of their ticket allocations to customers through competitions and promotions.
Lord Coe added that sponsors "were turning up," adding that they would not be naming and shaming those who did not.
On Sunday, empty seats were seen at venues including basketball at the Olympic Park, where troops filled the gaps, tennis at Wimbledon and volleyball at Earl's Court.
Around 100 seats at the gymnastics at the North Greenwich Arena were also given to troops.