Donald Trump. REUTERS/Brian Snyder Donald Trump took a shot at President Barack Obama on Saturday for not attending Justice Antonin Scalia's funeral services.

"I wonder if President Obama would have attended the funeral of Justice Scalia if it were held in a Mosque?" Trump tweeted.

The Republican presidential frontrunner added: "Very sad that he did not go!"

Obama visited the Supreme Court on Friday, when Scalia was lying in repose. But the White House suggested that the president's security detail would have been disruptive to the funeral the next day.

Trump has for years stoked rumors about Obama's past, especially the authenticity of his birth certificate. He was criticized last summer for not correcting a supporter at one of his events who accused Obama of being a Muslim foreigner. But he shrugged it off.

Earlier this month, Trump suggested that Obama made his first presidential trip to a mosque because "he feels comfortable there."