Today in Pictures: March 23

People gather at a memorial site for the victims of the Brussels attacks at the city's old stock exchange on March 23, 2016. Belgian authorities were searching Wednesday for a top suspect in the country's deadliest attacks in decades, as the European Union's capital awoke under guard and with limited public transport after scores were killed or wounded in bombings on the Brussels airport and a subway station.

PHOTOS: Brussels Blasts Kill Dozens in Airport and Subway Attacks

People write messages on a wall in Brussels' Place de la Bourse in an informal tribute to those killed and injured in the attacks.

Penitents take part in a Holy Week procession in Granada, Spain.

A Colorado State Trooper blocks the southbound onramp for I-25 in Monument, Colorado. The wet, heavy snow and strong winds have crippled travel in north central Colorado, shutting down some highways and schools and even Denver's airport.

The sun sets behind boats on Dal Lake in Srinagar, the summer capital of Indian Kashmir.

A member of the Ezzedine al-Qassam Brigades, the military wing of the Palestinian Islamist movement Hamas, holds his weapon during a rally to mark the 12th anniversary of the death of assassinated Hamas spiritual leader Sheikh Ahmed Yassin outside his former home in Gaza City.

A United Launch Alliance Atlas V rocket carrying Orbital ATK's Cygnus spacecraft lifts off from Cape Canaveral in Florida late on March 22. The Cygnus is scheduled to arrive at the International Space Station on March 26. Nearly 7,500 pounds of supplies, science payloads and experiments are headed to the station aboard Cygnus, including scientific investigations of fire in microgravity and grippers inspired by geckos, along with equipment to support some 250 other studies.

A group of nuns lobbying against the Affordable Care Act's birth control mandate stand outside the Supreme Court ahead of oral arguments in Zubik v. Burwell. The case is a consolidation of seven cases challenging the government's accommodation of religious groups that refuse to comply with the birth control mandate in the Affordable Care Act.

Bjorn, 5, smiles as he poses with an Owl butterfly during an event to launch the Sensational Butterflies exhibition at the Natural History Museum in London.

Supporters of incumbent President Denis Sassou Nguessu celebrate in the streets of Brazzaville after news of an early lead in the electoral results spread through the city in the evening of March 22. Congo's veteran leader Denis Sassou Nguesso has secured 67 percent of votes in his bid to extend his 32-year-old rule, partial results showed Tuesday, after a tense weekend poll. The results covered 69 percent of the total electorate, the chief of the electoral commission Henri Bouka said, adding that they did not cover Pointe-Noire, the economic capital and opposition stronghold.

Tuesday in Pictures: March 22