Updated

Athletes, officials and media from all over the world poured into Heathrow Airport on Monday for the London Olympics, the first wave of a record number of passengers expected to pass through Europe's largest airport for the games that begin July 27.

Heathrow says athletes from 50 nations will touch down in what is being described as Britain's biggest peacetime transport challenge. In all, the airport will handle some 236,955 passengers, breaking the previous daily record of 233,562 set in July 2011.

To cope with the deluge, Heathrow has enlisted some 1,000 volunteers to greet arrivals — 500 were working on Monday alone — and created special teams to deal with oversize items like Olympic javelins, bikes and other sports equipment. All wore bright pink to easily stand out.

Hundreds of immigration agents were also on the job to ease the long lines that have plagued the airport and there was an increased police presence, including sniffer dogs.

Rows of Olympic VIP buses then whisked teams and coaches to the Athletes Village in east London.

At least one athlete, two-time world 400-meter hurdles champion Kerron Clement, was less than complimentary in a tweet after the bus taking the American to the village had a hard time finding its destination.

Clement tweeted: "Um, so we've been lost on the road for 4hrs. Not a good first impression London."

Clement, who won the world title in 2007 and 2009 before losing it to Britain's Dai Greene in Daegu last year, is the defending Olympic silver medalist.

Heathrow usually handles 100,000 to 110,000 arrivals a day, but that was expected to swell to 121,239 on Monday, many of them Olympic VIPs, just 1,710 short of a previous incoming record on Sept. 4, 2011.

Another big arrival day will be July 25, two days before the opening ceremony.

"We have spent seven years preparing for the Games' challenge. Now we are putting that planning into action with thousands of extra staff and volunteers on hand to welcome the world to London," said Nick Cole, head of Heathrow's Olympic operations.

Also Monday, an official a "Games Lane" was opened along the vital M-4 highway from Heathrow into central London for Olympic officials, VIPs and athletes. More "Games Lanes" will open in other parts of London as the Olympics approach.

London has four other airports, but Heathrow is the only airport where participants can get their Olympic credentials, so it will handle the bulk of Olympic arrivals.

The London Olympics start July 27 and end Aug. 12.