London Zoo has welcomed two newborn squirrel monkeys to the troop in one week.

Adorable images captured by ZSL's zookeepers show the babies, born on June 5 and June 9 to two different mums, Avril and Francis.

Zookeeper Rowan Swainson said: “Both the new little ones, who we’ve nicknamed Teeny and Tiny, are doing really well – so well in fact, that Avril and Francis have started to bring them out of their cosy indoor dens, so visitors can now spot them hanging out in the trees.

Islington Gazette: Mothers Avril and Francis have taken their babies outside to exploreMothers Avril and Francis have taken their babies outside to explore (Image: Sheila Smith/ZSL London Zoo)

“Squirrel monkeys carry their babies on their backs continuously for the first six to 10 weeks of their lives, so we’ll only be able to find out if the youngsters are male or female when they start to explore on their own.”

London Zoo's twilight sessions start this Thursday – a chance for adults to relax and explore the Zoo as the sun goes down.

Islington Gazette: Visitors to the zoo's In With The Monkeys walk through may be able to spot the two new arrivalsVisitors to the zoo's In With The Monkeys walk through may be able to spot the two new arrivals (Image: Sheila Smith ZSL London Zoo)

Rowan said: “Luckily, human parents can sometimes take a night off and we look forward to helping our grown-up visitors enjoy a well-deserved wildlife break without the kids this July."

Twilight sessions are on selected dates throughout July. Visit www.zsl.org/ticket/twilight-ticket